Ontario truck doing pickup and drop off in Quebec

Been out of the biz for a while and not up on current regs, but if you're a Canadian citizen doing work for the carrier you work with, there shouldn't be a problem, I would think.
I used to do it all the time with a couple companies I worked for.
If home bound freight was slow or they needed a truck to do local or regional work due to power shortages they would give OTR drivers and OO's from out of province that were laid over a chance to make a few bucks instead of just sitting.

 

Only owners or operators of heavy vehicles registered in Québec and Americans are required to be registered in the Commission’s register. Other carriers must register with their respective administration and their attestation of registration is sufficient to allow them to put a heavy vehicle into operation in Québec, provided that this registration remains valid.

Commission des transports Quebec: Owners and operators of heavy vehicles​

You are good to go with your valid federal CVOR. Once upon a time, as an inter-provincial carrier, you used to have to have a Quebec Register Identification Number (RIN), but that no longer appears to be the case.