For our upcoming trip we will actually be at 5 different hotels, but I only really consider the WDW part a split stay.
Night 1: we'll stop at a Hampton about midnight, daughter will already be asleep in the car, take in one separately packed bag, sleep, shower, eat, leave early morning
Night 2-5: AoA LM room, because my daughter is turning 5 and this trip is all about her

but actually I am dying to see a new resort and love Lion King and LM too, so it will def be a great way to kick off the trip and immerse ourselves in Disney
Night 6-9: POR Royal room, once again because this trip is all about her, but by this time dad and I will want a little less characters and chaos, and they have a hot tub for us and a pool slide for Z. We actually sought out a hotel with a hot tub for this part of the trip.
Night 10-12: beach hotel for our daughter's first trip to the ocean
Night 13: some hotel on the way home, depend in what time we leave the beach and what time we want to get home the next day, it may be a nicer one and we will spend time in that city, or a cheapo for crashing and leaving early
We are doing a split stay at Disney for pretty much all the same reasons as everyone else: POR is cheaper than LM for the entire trip, we are not a family that will go that often (about every 3-4 years) so want to experience a lot and know what we like/dislike for return trips, and dad and I want a little more adult themeing than AoA the entire time but we really want her to get the magic of Disney by being in the LM room. But I will also say split stays seem to only work well if everyone is easy going, which we are, and my husband is extremely helpful and accommodating, he is looking forward to the difference in each resort. While I am one to totally unpack for more than a 1 night stay, I am also very, very organized and can have us repacked and unpacked in about 20-30 minutes. And since we are driving down we have the luxury of using our car for storage and extras.