We are split stay pros, and I created a thread to help split stayers in the Resorts board. Nearly all of our visits include at least one move, and some of our stays have been similar to yours--on purpose. You can feel free to reference it here:
http://www.disboards.com/threads/the-ultimate-split-stay-thread.3322505/
I would also make these suggestions:
1. When we stay on points, our rooms are generally not as ready as early as they are when we stay on cash. Plan to be "homeless" from checkout (or whenever you leave your resort) until 4.
2. I would make sure you pack efficiently. Packing cubes would be a great idea--just pack what you need for each resort in each cube. Also, a hanging toiletries organizer is highly recommended. The least amount of packing and unpacking you need to do, the better.
3. If one of your rooms is ready early, and you don't want Magic Band issues, I would recommend physically checking out of each hotel. We have had the issue of our Magic Bands not working at the new resort if we have been able to get into the room early because they are still active at the old resort. The same if you are a gift card user and don't want money hitting your credit card if you use your Magic Band for purchases. Since you are likely transferring your luggage via Bell Services, it's really easy to just visit Bell Services and the front desk at the same time upon your departure morning.
4. I would not plan to have any cold groceries. If you do, while Bell Services will refrigerate your stuff, I don't know how long or how far they go when they do luggage transfers, and would imagine that depends on how many people they have switching resorts, so I wouldn't trust anything to stay cold during the transfer process. Boxed items should be fine. But I also would strongly encourage you to just skip groceries: I think your best bet is to travel as lightly as possible.
IF you guys approach this with an adventure mindset and stay organized, multiple split stays can be a ton of fun and in no way a disruption to your vacation. It's a great way to easily visit resort restaurants without hassle, stay in a new and clean room each day, efficiently get to parks near the resort where you're staying, etc. In many cases, we have found that split stays allow us to be MORE efficient with our park time and with visiting desired restaurants. Good luck with your stay and enjoy!