Nope nope nope....I'm not cooking on my vacation! The thing I look forward to the most on any vacation is not having to cook! Plus, the time traveling between the parks and the hotel would eat up too much time. Been there, done that. I might consider renting a car so we could do some excursions, and we ARE planning to visit WWoHP at Universal Studios on our next trip, so it won't ONLY be Disney. But it's not so much Disney Overload that's the problem...it's DH's lack of patience combined with DS's tendency to have meltdowns. And it's not exclusive to Disney. It happens whether we go to my in-laws' house for the day, or go to a techniekdag, or for a weekend in Dublin, etc. Traveling is hard with DS, and I get that, but I don't think the answer is just to never go anywhere. That won't help DS to adjust, or to cope with uncomfortable situations, and it certainly won't make for a happy mommy, because I need a break sometimes.
I don't blame you. My mom cooks when wecre in SC and Hawaii, but anywhere else, she's like, "Nope!" Even last time in Hilton Head, we ate out more than usual. And being on Disney property spoils you. I actually like that I can walk everywhere or just get on a bus and a bus will take me to the front of the park and drop me off at my resort and not have to deal with parking. Parking is the worst. AK and the WPs are the only exceptions. We're usually over at the Epcot resorts, so I'm spoiled by the ability to walk back to my room from Epcot or DHS and be at the hot tub in less than an hour after park closing.
And personally, having a sibling on the spectrum, I agree with travelling if you can. You'll figure out what works for you and him. For us, we've figured out what works. Sometimes that means getting a FP for a specific ride first even though it may not necesarily be the most convenient (looking at you, FoP). Sometimes that means stopping and taking a break and getting a snack. And most of all, it means clear communication with him. We tell him what the plans are. He's usually okay with them, but if therecs something he really wants to do, even if it's something silly to us like riding an elevator at Pizza Rizzo's, we do it even though we're like, "Yeah, why?" As long as it's feasible and not against the rules, we let him. It makes him happy and lets us all have a good vacation. And conversely, if there's something he really doesn't want to do, he doesn't have to. It's pretty rare at this point, but when he was younger, first he didn't want to go on TofT, then later on EE. My parents with me had a once per trip rule with me on every ride, but with him, he genuinely did not want to do either of those two, and they did not force him.
As for your DH, just know that he's normal. He really is. My dad stopped going to malls when my brother was younger because every time they would go to a mall, my brother, being a typical boy, hated shopping, and would melt down, and my father didn't feel like dealing with it. My dad loved going to malls and shopping. He still will drag you into every gift shop in WDW on the off chance that they might have something different in this one even though they usually have the same stuff in each one. But my dad really didn't do my brother any favors because now, every time we walk into a gift shop in WDW, my brother does not want to be there, and he gives my dad more grief in shops than he does my mom or me. Heck, in Hilton Head, my grandma and I went in a department store with him and I tried on clothes and shoes while having him hold my purse, and he was probably bored out of his mind, but he was an angel. And rewarded for it.
But he never would have been that way with my dad. He would have thrown a fit about being there, making them both miserable. Instead, if my dad had figured out how to deal with that when he was younger, as my mom did, he wouldn't be this way now. That being said, he has gotten a lot better. It's been an education process, as I'm sure it will be with your DH. But know that he's normal, and he will get there, but he's not Mom, and it will take him longer. But he will get there, and you may have to insist that he still do things like go on vacation, and it will be worth it in the long run.
On a side note, in just dealing with your DS, have you talked to your DD about any of this? Coming from the perspective of being a big sis, I have sometimes had insights into my brother that my mom hasn't. She's said before that she'll talk to me about something going on with my brother, and she'll get anxious that it's a new behavior, and I'll say to her, "Mom, he's a teenager. Of course he's doing that." And then she calms down. Keeping me in the loop gave them insights, as well as gave them peace of mind knowing that there was someone around who knows him as well as they do. And it made me feel valued in m family knowing that my opinion and insight meant something, and I did two separate projects in college for autism advocacy. Just a thought, it might not work for your situation, but you might be surprised what kinds of insights your DD has. And you want to keep a check on her too to see how she feels about this, because she definitely has an opinion and feelings on this.
BTW, Seasons at non peak periods, excellent spot. You get a DAS for Soarin', get on Living with the Land, get a snack at Seasons, and then after 15-20 minutes, he's rarin' to go, and the DAS is good. There's also seating there that's away from noise and people, so if you start to sense that he's heading into meltdown territory, sometimes a sensory break is an excellent thing. It's my antimeltdown formula for when I have my brother and my parents aren't around, and he very rarely melts down. If you want my desensatize spots for when you go back to WDW, let me know. I know them partly becuase of my brother, sometimes because my migraine brain needs 30 minutes away from noise and people with some caffeine.
A few times told his Grandma she needed to come get him and he needed to 'stay with her a few days.' lol. His Grandma loves him to death and enjoyed spoiling him.