Just an observation, if the Confederation of Texas, however it logically arrived at those borders, is as mapped, it would mean it lost a conflict/war over establishing a port on the Pacific. And it would mean they would be coming back for a second, third, etc., to attempt to seize territory on the Pacific in the future.
I find it strange that the St. Lawrence river is Quebec's border: it should be it's heartland. Losing the south-east shore just seems absurd.
As far as naming goes, it is very unlike it would be called "Quebec" at all. It would either be called Canada or New France depending on the status of the other French provinces at the time of independence.