We always do split stays and have done it with a party of 8. We have done a split of 5 hotels. This time we are doing a split stay of 6 resorts over a 17 day time. People say we are crazy, but we like it and my kids love trying the different places. We plan accordingly and never lose real time in switching. We have lost maybe in loading driving and unloding. This time we will not have a car so will depend on the resorts moving our luggage. We never really unpack so it works ok for us. We consider the resorts like an attraction.
We recently did a split stay at Poly and BC over 8 nights and loved it. We felt like we actually GAINED time because we were generally closer to the parks and restaurants we planned to visit on a given day (only had to use the buses on our AK day). Plus we got to experience two different resorts (like two vacations in one).
In fact, we liked it so much that I'm planning another split stay at 4 resorts over 12 nights. Originally, I was going to just do a 2 way "lodge themed" split at WL and AKL because I really want to experience those resorts. But I couldn't bring myself to give up the ambiance (and Monorail access) of the Poly and the location of BC for visiting EP and HS. So the current plan is 3 nights at each of WL, Poly, AKL, and BC.