I don't know the exact budget for the Frozen ride. Photodave again said Frozen at Epcot was $75 mil back in 2014 (apparently after receiving a massive budget cut). I believe this included the restrooms and meet n greet next door, though i'm not 100% sure. I was just posting the $50 mil number as a ballpark figure for what seemed to make sense.Re: Budget
Even is $50 M is the number (which I honestly don’t know, but it sounds a little too low to me).
Remember that the exterior isn’t even changing too much, and one of the reason Frozenstrom had issues was the ride infrastructure (which I believe Splash’s many refurbishments have already done the brunt of the work on).
As I said, the other number I heard for PATF (which again didn't come from WDW Pro) was SIGNIFICANTLY lower than $50 mil. Even if the ride system doesn't really need any work, we're still probably looking at a gutting and replacement of at least 90% of the interior scenes and animatronics. The only scene I could see not really needing too much alteration is the Riverboat finale (the animatronics there will still probably be removed though).
Splash Mtn is much longer and contains far more scenes than Maelstrom ever did. The scenes are also way more detailed and packed with AA's than Maelstrom's. So it'll look even worse by comparison if the overhaul doesn't add back in a similar level of physical detail and figures to what it currently holds. Something that I feel is reasonable to say isn't possible with a $50 mil budget (let alone a lesser amount). Heck I think it's extremely unlikely they could do it on a $100 mil budget.