I recently had a somewhat similar situation where my arrival to the hotel was delayed about 14 hours due to a flight schedule cancellation/change. I contacted the hotel by phone and spoke to the front desk advising of my delay and requested the hotel hold my reservation until I arrived. I followed up the conversation with an e-mail to the hotel confirming the late arrival. My e-mail was actually a reply to the "Welcome/Greetings" e-mail that my hotel had sent out a few days prior to my arrival. I received an e-mail back from the hotel several hours later confirming they would hold my reservation in anticipation of my next-day arrival...and I was all set.