I'm glad you were able to get this accomplished. I also had a soon-to-expire 35K-point business AmEx Free Night Award (FNA).
[Technically, Free Night Certificate (FNC) is used by Hilton, although an FNA does require a certificate to be attached, which causes terminology confusion.]
Because of all the AmEx credit card FNA denials reported here or in another thread, I just went ahead and took a frivolous overnight SPN-GUM trip to use my Marriott BONV°Y AmEx night last month, before the FNA expired.