I bought the Groupon last year and wasn't able to use it during its promotion period. Basically, it was $225 for a two-person overnight and half-day ride (1/2 price). Groupon, of course, retains the purchase value if not used before the expiration date. So my wife and I were quite offput when trying to book a similar package (on sale for November stays) and use the purchase price as partial payment. The price on the website is $350, so we (naturally) assumed we could present the expired groupon and add $125.
Nope...Dwight wanted us to give up the Groupon + $225 to book this trip. This led to a very unpleasant conversation. He looks at things backward...that the promotion amount (the discount) is what needs to be paid, not the difference between the credit and the current pricing.
The place may be great, but we'll never know. Groupon stood up for us and gave us our money back. If you buy a Groupon, use it during the promotion period or be prepared!