Difference between Montreal and Toronto for winters is day and night.
I'm in Toronto. Over last winter we had 10 liveaboard boats at my club and 11 in the water storage. Granted last yr was a mild winter. I only used my bubbler(s) once for a 24hr period. Otherwise it was the routine of getting out of the boat, turn it on, have my shower, come back and turn it off. And I was good for another day without having to run them. And I did need it I would turn it on in the evening while having dinner.
Living aboard on the hard? That’s insane. I may a well just move into a walk in freezer with a tent.
Each boat at my club has access to 120amps, the pedestal each are metered.
I had three 30amp cords coming into my boat. One for the boat itself. I don’t run heaters on the house power. The other two shared power with 1500watt oil filled heater (which was on pretty much ALL the time), 1500w ceramic heaters which I never ran above 900watts(Only turned on when I would get back to the boat after work) and my bubblers.
I’m thinking this year there will be more liveaboard’s from what I have been hearing.