We did a split stay this Dec. I was worried at first because we are the type of people who totally unpack everything and move in! However, we switched resorts after 2 nights (and then 5 more nights at the 2nd loc.) so we were able to do the 2 separate suitcase thing, as suggested above.
It was like getting to go on a whole other vacation, because for us the resort feel really impacts our Disney experience. And, it wasn't a big hassle at all. However, we had a rental car and we have APs, so we were easily able to move and store our luggage, and we didn't have to worry about the complications of switching park tickets or dining plan days.
I can see how, if you wanted
DDP for the whole trip, a split stay could get complicated. (Otherwise, you would book a package for the first part--getting as many tix days as you need--and book room only for the 2nd part.)
I was unsure at first, but it turned out that we really enjoyed the split stay and it made the whole vacation feel longer.
I wouldn't have known if I didn't try.
But, to each his own.