Ha! A question I actually have practical advice for! At last sleeping in a big puppy pile becomes useful!
1) Wow, you guys are big! We sleep four people in a California king with no problem. However, at our "other" house, we only have a queen, so we are in the process of purchasing another queen to place next to it. This is a solution we have employed in hotel rooms with no problem, but I know that you can also purchase an adaptor to cover the crack between beds, so no one gets lost or even...eek...pinched.
2) Speaking as the person who gets stuck in the middle, solve the blanket problem by buying multiple blankets and overlapping. Then the person who is in the middle can slip out through the overlap (the person in the middle usually slips out from the middle by sliding out of the end of the bed) and also the person who has to sleep in the middle of the furnace can throw off blankets at will.
As for waking the others...well, that's just a hazard of sleeping so many people together, I think. We have no practical solution for it, which is sad because I'm up multiple times in the night so everyone else is, too.