Vermont just came live for June dates (10 minutes ago it wasn't even on the list). I just booked 2 appointments for June 30th. It's exactly the week I wanted so I'm happy. I'll keep checking once in a while for Champlain or Montreal since they are closer for us, but I don't mind the 2h drive if we have to.
I can now stop checking the TTP website obsessively every 10 minutes. But if someone sees Champlain open for appointments, please post here. Thanks!!