The disastrous Canadian campaign is still studied in the world's military academies.
I believe at the time the rebels held Montreal and were besieging Quebec, with not unreasonable hopes of taking it, and with it control of Canada.
It seems highly unlikely the Congress could have known the Dec. 31 assault on Quebec had failed, with Montgomery killed and Benedict Arnold, the real moving spirit behind the campaign, seriously wounded.
Given the vulnerability of the St. Lawrence to a naval assault, it doesn’t seem likely the rebels could have held Canada against a serious counter-attack in any case. But they dang near conquered it on Dec. 31.