Right now, no, because it's my top choice and there's still a slim possibility that something will come through. But if they come back and tell me that funding definitely isn't available, then yeah, I will turn it down because I can't afford to gamble like that.
Not sure if you're in musicology or composition, but you might not want to get your hopes up. When I got my admission notification (musicology) I was told that at this time they can't promise funding and asked to let them know if I got an offer elsewhere. I know the grant freezes aren't helping things but it's still incredibly disappointing.