By the Agudah Convention last year, many people stayed in the Holiday Inn Express. Before Shabbos, we spoke to the management and they agreed to help us in any way they can.
They covered the sensors by the front doors so the doors stayed open. When we had to get in our rooms, there was someone who had a master key willing to come up with us. They allowed us to use crock pots in our rooms as long as they were safe. They let us bentch lecht in a room on the first floor. They really tried to do everything we asked.
If you speak to them beforehand, they will want to help you.