Here's the thing: you only do as much at WDW as you want to.
The BEST advice I ever got about a WDW trip, better than FP+, better than rope drop, was along these lines:
Don't give any ride, attraction, parade, meal, FP the power to "make" your vacation. Your entire group will only be as happy as the least happy person-- and that role will shift throughout the trip. When someone is tired, stop. When someone is hungry, get a Mickey Bar for everyone. When someone needs to go back for a swim or a nap, make sure they do.
FAR, far better to be able to say: "We missed ___. We were simply too tired to make that FP; we'll have to see it on our next trip. But we had a wonderful time." than to say "Yes, we saw ___. J was cranky, T had a tantrum, and B and I had a huge argument over how to deal with the kids. But we saw it."
So my point is that you can warn everyone that there's lots of walking. But also let them know that WDW transportation is easy and free, and that if they need a break they can take one. They can go back to the resort, put their feet up, nap, and call you when they get back to the park or meet you for dinner.
Yep, they may miss Soarin and Frozen Ever After. But they'll have a much better time, and so will you.