Thanks for your replies! ^ I guess I'll take advantage of the offer and see what happens upon check-in.

The room rate is definitely inflated, it's the weekend of the bi-annual Grand Prix de Monaco Historique (May 14th - May 16th). I was surprised I could even use my free nights cert along with the Garden View suite upgrade since those suites are going for 1749 euros/night. Originally I couldn't use the suite cert because the Garden View suites were fully booked, but I checked the website last night on a whim and saw that it was available again. Immediately called FPC to apply the suite cert on my reservation to lock that suite down.

Already super excited that I get to stay in a junior suite for free on a race weekend, but if they'll take 128 euros a night for the Riveria suite I'm more than happy to pay that!