I second the suggestion to see Yeehaw Bob at POR. I use an
ECV and I can't remember if the boats at that resort to Springs handle
ECVs. You could always use the Minnie Vans to get there. On the Lyft app there is an option to summon the ECV friendly Minnie Van. I like it for resort to resort trips. Get to Yeehaw Bob a bit early if you can.
Have you been to the Grand Floridian spa? It's lovely. I've taken my adult sons there with me for manicures (you don't have to get polish). The relaxation room they put you in to wait is worth the price - it's so peaceful back there. I could make a day of that spa and I'm not a spa person.
I have trouble walking (getting both knees replaced one at a time currently). I can do some rides but I've gotten more into the entertainment stuff. I have REALLY enjoyed the after hours parties. I did
MVMCP and
Jollywood last year and those were great - lots of special entertainment you don't get otherwise. I also think the dessert parties are fun for the evening fireworks. Not sure how much you want to spend on extras.
That Candlelight Processional is not always a "run into the park and catch it" experience depending on who the narrator is. Some Narrators are wicked popular and the lines start hours and hours ...and hours...ahead of time. When the schedule comes out check who is there during your trip and - easiest thing to do - book a Candlelight dinner package and you can guarantee your seats. We saw John Stamos last time and Neil Patrick Harris was there the next night. The Epcot crowds around the theater were insane. INSANE. We saw people trying to line up around noon....or maybe earlier. My son is a CM and I go to WDW a lot and I just wouldn't roll up on the Processional unless I hadn't planned to go and saw it wasn't busy - which has never happened - haha! You might luck out with a less well known narrator that people aren't interested in as much?
Do you like to dine out? So many options but one that surprised me was Coral Reef - we did our Candlelight processional package dining there and I loved sitting and looking at that giant wall of an aquarium - very cool. Space220 can be interesting (lunch is cheaper).
You can rent some sort of kinda big boat over at the GF dock and it wasn't all that expensive for an hour. You drive it. I think that could be kind of fun. It was like a pontoon boat or something not a tiny boat. $49 a half hour. I think other marinas rent them too:
https://disneyworld.disney.go.com/recreation/motorized-boats/
The Keys to the Kingdom tours and other tours are great - I did that one on an ECV.
The glassblowing guy on Main Street in the MK is fun to watch.
One thing I've not done but watched people livestream it on YouTube is renting a golf cart over at Fort Wilderness campground and touring all the Christmas/holiday decorations that people set up at their campsite - they go all out and it's crazy looking. It's popular and I don't know if you can reserve a golf cart in advance but I'd try to make a reservation for one and maybe eat dinner over there. Of course it's better to go after dark!
Also make sure you ride Living with the Land at night because they decorate it for Christmas. It's there in the day but you don't see all the lights.