I love split stays and do them almost any stay that is 4 or more nights.
If you have a car, move them yourself. In December you can put them in your trunk. If you are going to MK, drive to CR and drop them off.
If you are relying on Disney you should ALWAYS call from your room. This will “open a ticket” in the system and if anything goes wrong they can easily find your bags. Bell Services will come to your room and give you a claim ticket.
Some people will tell you to bring your bags down to bell services. Usually that is fine. If there is a problem, it can get complicated.
Your bags most likely will not get to the next resort until after 3:00.
Examples of lost bags both ways:
AKL to Poly- I brought the bags down to AKL bell services. Poly received their internal delivery. My bags were not there. There was no record of my bags. I had my claim tickets but since I dropped off the bags no one put them in the system. Three hours after I started asking (45 minutes before my CG ADR) a liner CM contacted AKL bell services, my bags were in the corner there.
AKL to WL (see a pattern?)- at WL called down to bell services, bags not there. Give us 10 minutes and we will call you back. They called back within minutes and told me my bags would be there within 30 minutes (AKL sent them to FW).