@Jessa85
I'm not sure what your plan is (and not asking), but I'm assuming (again, not asking) that you plan to communicate to him once he's back that he isn't welcome at the house. If he is going to find out you want a divorce before you move the money you run the risk of him 'getting in there first' and either taking the lot or freezing the account. So best be ready with your finger on the trigger once you've told him.
Do you know if the airline he flies has wifi? If not, chances are he'll be 'out of mobile service area' in the air and you can move the money without him getting the notice until he lands. Of course, that will give him a 'head's up that something's up'.
One way you can tell, if you can 'see' him on your 'FindMy' and iPhone, is that if there is no mobile service FindMy will only show his last known location. My son flies frequently for work and he's explained to me that if it shows him at the airport when he's actually in the air it means there's no mobile service on the flight. I guess I'd asked him if he'd missed his flight one too many times lol.
Good luck, you're a real champion.
Oh, also, you may want to move that over to your Monzo account at some point if your 'usual' account is at the same bank as his. My son was advised that he should have NO accounts at the same bank to avoid any 'slip ups'.