Wow! That's terrific. Congrats.
IMO, I think MR hotels are more willing to work with it's MR members than some of the other chains and programs.

I have had business travel changes a few times in the past and needed to change locations. The hotels have been very gracious is allowing this.

However, I have never had an issue with doing an advanced purchase rate. (tend to stay away from those since they tend to be risky).

Congrats Again!