We just came back July 5th thru july17th
We prepared for the worst , we are from CT. it was worse in CT when we left on the 4th I thought. Yes it was hot but we lucked out with some overcast days, no rain outs, a few storms after 5:00. Line werent bad, The plan is get to the parks by 9:00, use EE when you can, we were goinging back for rests by 1 to 2pm, nap have dinner, and back out for while, This was the longest we have ever stayed , This time we had APs ,This schedule only works if you have passes for all days Im sure it would work for a 7 day vacation If you dont have a pass for all days you tend to try to cram to much stuff in on a 5 day hopper for a 7 day trip. we have done that. If you try to do a whole park in one day you will crash!
Ps July 5th in MK wasnt even crowded till 1:00pm, every one was sleeping in from the show on the fourth night before.
Good Luck and dont be scared
Jack