I wouldn't give up on dining reservations yet - do you have a
MDE account? If not, make one and get the app on your phone. Then go on and start looking for the meals you might want - keep in mind people change plans everyday and things open up, especially once you get under 30 days, and even week of and day before, as people finalize plans, and cancel what they don't need to avoid fees. With the app you can check for them whenever you have time throughout the day. Also find the December cancellation thread on the Restaurant forum, and sign up to watch it. People will post what they are going to cancel, and you can coordinate to try and grab one, if it is what you are waiting to get. and then sign up for Touring Plans Reservation Finder as PP mentioned - it is free, you just have to set up an account, and can put requests in at a time, and they will text you when one pops up, and you can try to snag it. Between all of these, I have been able to get mostly everything I wanted for each trip, and even helped friends going Christmas week, who didn't book till November - even got Ohana!
As far as plans, be ready by your 30 day mark(since you are offsite) to make any FP you would like - you will need to link tickets to your MDE acct before that to be eligible. You will want to FP Soarin if that is your priority, since you can only pick one of the top three rides(Test Track and Frozen) for your 1st FP, and two others for your other two, or be there at RD to do that, and FP one of the others. If one of your special restaurants is in Epcot, you could also try to do the Candlelight Processional Dining package to enjoy that show if you are interested. Pandora in AK has been crazy since it just opened in May, especially at busy times like you are going, so you can try to get a FP for one of the two rides(FoP will probably be unavailable, so you can try for the Navi River Journey). Otherwise you will want to get to AK at least an hour before opening, or maybe two that week

to not have a multi-hr wait, or can try at end of night to get in line. Pandora area is lit at night, as well as Tree of Life to check out. There is also the River of Light show if interested, which you would want to do dining package or FP for if you don't want to line up early.
I don't know if you have been at the holidays before, but I would not want to miss seeing the castle lit in MK! Main street is beautifully decorated as well, and on the 30th they show the same fireworks that you could see on NYE if you are into that, just get a spot early and be prepared for crowds!