We did this for a quit a few years, until we bought a second contract that gave us enough points not to have to worry so much about conserving.
What we would do is usually arrive on Friday and stay Friday and Saturday(and sometimes Sunday)in an on-site hotel(usually a moderate or the Swan/Dolphin using the nurse's rate) and then move to the DVC property for the remainder of the trip. We always finished with the DVC property though, not the regular hotel room. That way we could still pack less, knowing that in 3-4 days w'ed have access to a washer/dryer, and the end of the trip was spent at the larger and more relaxing unit and associated relaxed pace.
If you stay at a Disney resort, they will transfer your bags. I do not believe they transfer your bags from any of the Hotel Plaza Boulevard resorts or from the Swan/Dolphin, as they are not technically Disney-owned resorts. If you have a car and stay at one of the on-site but non-Disney owned resorts, moving still shouldn't be a huge issue.
I actually didn't mind changing resorts mid-trip...in my mind, it gave us the opportunity to get a flavor of all the resorts, and since we always pretty much did Disney-owned, we used their bag transfer service and it was very easy.