I would define Cold as anything below Zero with winds to drive wind chill to unsafe temperatures .......From Copper Harbor to Monroe in Michigan that can be ANY day between August and May.
Cold for an EV is anything below 45F
All EV's seem to have the same issues. I had a Model 3, still have a Volt and a Model X.
They all like to fog up easier than an ICE. I think most ICE cars always pump in some fresh air (even if on recirculate) and they can afford to heat it, for no additional cost. Auto HVAC works fairly well. But you can save a little energy if you manually run it and keep a close eye on it.
I don't think heat from ICE engine makes a huge difference.
The Model S/X does have heated wiper blades which is nice. I don't believe the Model 3 did.
The Model S/X has heated wheel which is nice. Model 3 does not. But it's more instantaneous heat made up for it.
They all have heated side view mirrors.
They all have powerful rear window defogger.
They all have powerful HVAC fans.
They all have powerful heated seats front and back.
You will hear a lot about Frozen Frameless Windows. Tesla could do a lot better there. There are ways to deal with it. If you think it's frozen, Preheat first to be safe. You can test windows with the Mobile App Vent. Not good if you manage to open the door without the window automatically dropping down. Needs more TLC than average.
Model S door handles can freeze.
Model 3 door handles can freeze.
Model X door handles barely freeze (because they are mostly just a button).
Handles need way more TLC than average, except Model X.
I highly recommend a garage with a Tesla if you live in Snow Country. You can get by without, but it's a bit more annoying than an ICE when covered in Ice. The more Ice and snow covering avoidance the better. It's not that they will outright fail, it's that they need a fair bit of TLC when all iced up.
Snow traction wise. Model X is the best AWD I've ever driven (I'm sure S is the same). Model 3 AWD was probably the worst I've ever driven (it's still an AWD and better than RWD or FWD) but disappointing. I always run snows on anything with 4 wheels and I recommend others do as well that live in snow country. It's cheap insurance.
Because of the cost of heating and sometimes preheating it's really a good idea to go for the absolute maximum range battery. Performance and max size wheels cost quite a bit in range.
One other thing to check is insurance. You will see wildly different rates for Tesla's. You can find reasonable rates if you shop around.