And just so we're clear, Jeff, if you're going to be staying with Grandma, you will provide her with some form of compensation - be it monetary or in-kind such as mowing the yard - and she will not perform any domestic duties like laundry or cleaning for you. That woman already spent half her life raising her own kids; she doesn't need to spend the other half raising her kids' kids. At the very least, let's aim for a situation where she's no worse off for having you than if you weren't there.
You know the woman will have to wait on him hand and foot. Poor thing.