The border closure affects land crossings outside designated categories like commercial freight trucks or exceptional circumstances of some sort (which would not include holidays).
Air travel is still allowed which is gamed in some cases.
A politician going to any of the destinations shown would most likely fly. Especially to Hawaii ;-)
No laws were broken, but considerable cynicism towards rules was displayed. A number of politicians have had to resign, starting with Rod Phillips, Ontario's Finance Minister who flew to St. Barths, which oddly enough, seems to have fireplaces.
(from my last link:)
Ontario Finance Minister Rod Phillips resigned on Thursday after returning from a two-week vacation in St. Barts, where he had been since Dec. 13.
Jason Kenney, Alberta's Premier, first only scolded his errant flock, but has now penalized some of them.
This article lists some of the others.