April in MCO can have some hot days too. No need to walk to MGM from BW, the boat gets a nice breeze and chance to recharge those feet
Sounds like you just got back & trying to possibly space out your trip but August is seriously HOT in MCO. May & June not as oppressive, July even seems better than August. Trip should be doable with the afternoon break you take, especially with a teenager vs kids sweltering in a stroller. Dress for the weather in wicking clothing and a hat with SPF. You need to set your expectations accordingly and look for afternoon shade.
JMHO the afternoon rain makes it even more steamy, less humidity gives better real feel temp.
There is nothing @ Universal that compares to that long, shadeless walk from the front of Epcot to World Showcase area. I swear i had a pair of
crocs melt on the sidewalk once