Jingle Cruise is available outside the party, you'll just wait longer unless you get a fastpass.
I think those are the two most popular character spots for the party, their line doesn't really shrink much, or at least didn't seem to anytime I've walked by them. If you aren't interested in the rides during the party, I would get in line for the dwarves prior to the party start and get them out of the way first. You'll want to be able to hang around the front of the castle for some time to be able to catch both shows, the fireworks, and first parade, basically 8- 10:15 assuming similar show times to last year (and that doesn't include finding a spot time), starting with Frozen, then parade, then Mickey stage show, and ending with Fireworks with some hard to fill dead between. I wouldn't spend much time getting cookies and hot chocolate until later unless you really want one early, they have lines early on and no lines after the first hour, you should be able to get the first cookie on the Main Street bypass before the party starts.
Personally I would avoid the first parade, but I like the lesser crowded second one.
To do everything I would do this (and this is assuming the times are the same as last year):
6:15 Frozen castle show (not necessary to us, I like seeing the castle after the show more than the show itself)
7:45 Totally Tomorrowland Christmas Show
8:10 VoicePlay (not necessary to us, nice acapella show)
10:00 Holiday Wishes
10:30 Mickey's Most Merriest castle show
11:00 Parade
Then fill in the gaps with characters and cookies.
This way you'd be in front of the castle for only the a little over an hour instead of over two hours.