I love split stays! This past January we couldn't decide between resorts so did a split stay between WL and AKL. It was great! It was like two vacations in one. In a week we went from the Pacific Northwest to an African Savanna. In May I spent two nights at POP, then rented DVC points for five nights at BWV, then added two final nights at POP. Sept 17th-24th I took my son and D-I-L to WDW and we spent all 7 nights at POP because my D-I-L didn't want to do a split stay. I really missed switching. In Dec I'm taking my mom down there and we're doing a split stay between POFQ and CSR. I can't wait!
WDW makes splitting a resort stay very easy. Just call the morning you're ready to switch. They'll come get your luggage and transfer it to the other resort. You hop on a bus to the nearest park, then hop on another bus to your new resort and check-in. When you arrive back that night from the park either call for your lugage (if you're in a deluxe) or if you're at a value the luggage will already be in your room waiting for you.