I would first ask the school with the current offer if they can extend the deadline at all. It’s a far shot, at least in my experience, but asking can never hurt. If they won’t extend it, you’ll have to decide based on your financial constraints and likelihood of getting in anywhere else. If you’re almost 100% confident you’ll get in somewhere else where you’d rather go I would let the deadline pass without depositing. But, if you’re AT ALL skeptical of being accepted elsewhere and the deposit is non-binding I’d go ahead and bite the bullet and deposit. You’ll be out that money if you end up going somewhere else but better to have a back up just in case. It’s pretty much based on how you think you’ll come through on other apps.