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Join Date: Sep 2009
Location: Minneapolis: DL DM charter 2.3MM
Programs: A3*Gold, SPG Plat, HyattDiamond, MarriottPP, LHW exAccess, ICI, Raffles Amb, NW PE MM, TWA Gold MM
Posts: 100,398
If the reservation is confirmed in the legal currency at the time of booking, the hotel shouldn't be able to change the rate later, almost no matter what happens. Of course, if the hotel totally ceases to operate, the reservation of course would be cancelled.
I would think that if/when the currency is changed, existing reservations would be changed to the new currency at the official exchange rate at the time of the switch. IIRC this is what happened when a lot of Europe initially went onto the Euro.