A little bit more technical info:
A standard NHL rink is 200 feet long and 85 feet wide, with goal lines 11 feet from the end boards.
International ice is 210 feet long and 98 feet wide. Goal lines are 13 feet from the end boards. The extra room can sometimes lead a team to play a more passive “positional” defense, angling attackers away from the goal rather than pursuing the puck carrier.
Doesn’t explain why although 210ft = 64meters and 98ft = 30m which doesn’t make any more sense than 61m x 26m (which would be the nearest rounding)