We do not generally recommend involving the new tenant at this point, because it is not really their problem. Since the contract with the new tenants begins on January 1st, you can only follow through on your contract if you have clear possession of the unit (for example, if the old tenant returns the keys) so that they can move in on the date agreed to. If you do not have possession and the new tenants do agree to bring the move-in date forward, then you can put the account in their name WITH THEIR CONSENT. Otherwise, I would say that you may have to temporarily be the account holder.