Hotel Block Issue

I need some opinions on whether or not to change the hotel the block is at. I reserved the block at the DoubleTree a year ago. They only let me reserce 15 rooms despite my insisting we'll need at least 30. I offered to sign a contract saying we'd be responsible for unbooked rooms in the block, but they refused. My invitations haven't even gone out and the block is almost full, so I asked to add rooms. They told me the hotel is at capacity so I can only block 20 rooms total. This is not enough for everyone. I suspect they knew this a year ago and strung me along.


Should I have everyone cancel their DoubleTree reservations and change the hotel? The Marriot has plenty of space for everyone. Others have suggested to just let the block at the DoubleTree fill up and everyone else can find another hotel (there are plenty). We've already hired a shuttle to go from the hotel to the venue, so I'd like everyone centrally located.