Hi,
Yes we stayed there a couple different years with that offer. Of course it was always rack rate of about $140 or so for the night you paid for but it still made it work out to $70ish a night.
In the past it usually started in Nov. and when we used it on 2 different years the coupon said till the end of Feb. but the HIFS said there hotel will only do it till the end of Jan. And both times we used it were in Jan.
Hope you have good luck finding it this year and using it.