make the switch, but find out what they find good notice. If you decide you want to go back later(for whatever reasons) you don't want to have burned any bridges. I've had boarders give a month, 2 weeks, a week, and I've had some just cut & run with no warning. Generally, stable owners kind of have an idea when their boarders are getting ready to leave, and Usually it's not an issue any which way, but it does sting when you're out of town, and you get the phone call from the temp barn manager ...'susie q just loaded up her horses, and is rummaging the tack room....'
Be considerate, and keep the door open. You may never go back, but you may get there, and find it's not as great as you hoped...Good luck, and enjoy the trails!
Ask Often, Demand Nothing, and Reward Generously.