Some people view a fresh start as a way to begin anew and it works wonderfully, but for others, the stability of what they already know seems to be important and the stress of moving and pressure to begin again is too much in early recovery.
Only he can decide what is right for him, and I agree with Anvil, if your heart is telling you to go, you should maybe listen or you may come to resent him and staying, especially if he relapses, which often happens. But he could also relapse in the new place--there is no way to know what is "best" for another person.
I hope you both find healing and happiness in whatever form it finally takes--