I paid for alcohol in multiple countries between 18-21 years old. Do you think the US Gov cares that much about anything non-terror to seek foreign transactions?
Canadian media thinks it is not worth the risk [0], especially in the light of the statements made by US officials [1].
[0] https://globalnews.ca/news/4140898/legal-pot-data-banned-us-...
[1] https://www.politico.com/story/2018/09/13/canada-weed-pot-bo...