Originally Posted by
Isagarch
what is the worst that could happen, they revoke my visa and ban me from ever returning to the US?
They can cancel your visa and prohibit you from entering the US for a number of years (depending on how long you were out of status in the USA).
Can I be arrested?
By whom? You are in Canada, so American LEOs have no jurisdiction over you what-so-ever. You wouldn't be arrested even if you were still in the USA because being out of status is an administrative violation, not a criminal one.