We don't have anything specific in our Code, but we have recently dealt with this one.
We used a two-tiered approach with an indoor rink that is nearing completion. Based on similar facilities, we determined that their normal daily operations would required X spaces (I think about 30). They provided those on-site. Then, we looked at the 450 seats around the ice and required them to show that a total of 113 spaces (1 space for each 4 seats) are available either onsite or through recorded parking agreements with nearby property owners. In that way, we covered the anticipated daily use on-site and the special event use through shared parking. The rink is in the downtown, so there are also three public parking lots (about 200-250 spaces) within two or three blocks.
In another instance, we have a seasonal outdoor rink on City property. The adjacent parking lot almost always has 15 or 20 cars in it. On a sunny Saturday afternoon in January, there might be twice that many cars. There is also a lot of use on weekend evenings (it is lit until 10:00 pm).
Be sure and use local examples, though. The rink here doesn't have anywhere near the use that your's will. We don't have the big recreational hockey leagues that you do. Our users are mainly tourists and a small group of locals. Isn't there an outdoor town rink in North Conway, right on the common? It might be similar.