This is a little off topic but since you're worried about how far your 77 y/o has to walk at the resort I have a suggestion, you might want to think about how active your 77 y/o is in everyday life, how well they might do in the high heat and humidity we have here in FL, and how are you planning on attacking the parks. I say this simply because we took my 71 y/o dad who was still working both a full time and part time job at the time, plays golf a lot, and is generally a busy guy but he found the pace with long days and humid heat down here to be hard to deal with. And he use to live down here but hasn't for about 20 years. We ended up getting him a
scooter and he did great using it as needed.