Well, you may be able to get by using just the seat and steering wheel heaters on many trips. I'm not sure if the PHEV will still insist on warming up the engine even if the climate controls are off though. Reading about Northern Europeans in the forums, many use a small electric heater to warm the interior prior to driving.
The PHEV doesn't have the range of a Volt, especially in the winter. If you take frequent short trips, in might be OK.
I don't think the Niro EV has been released anywhere in the world yet, but the Ioniq EV is available. Only in CA in the US, but there are tons available in Canada. It would probably be pretty easy to license one here as there is no engine to certify. If that car fits your needs, you want one with the CCP package that includes a heat pump, heated rear seats, and a battery temperature management system. I don't think you would be eligible for tax subsidies in the US, but the 25% currency difference may be just as good, even better if you get a used one where the owner has already earned the very generous Canada federal and provincial subsidy and must sell at a substantial discount from MRSP to compete against new cars.
Back to the Niro, if I'm not mistaken, Alex on Autos (YouTube) recent review of the Niro PHEV specifically discusses that a larger driver may have difficulty fitting a rear facing child/infant seat behind him. Worth checking out. The HEV and the PHEV have identical interior dimensions in case you cannot find a PHEV to check out. Bring your child seat to the dealer. The Ioniq is I think seven inches larger in length, but I'm not sure there is any more rear passenger space inside than the Ioniq (less rear head room for sure, but you won't care about that for a number of years).
The Kia Soul EV or the upcoming (probably 2019) Hyundai Kona EV might also be good alternatives to consider for your use.
I could probably handle just the seat heaters for many trips, as I try to minimize my heat use to save electric range in my Volt. But my wife certainly would not. And she drives it about 30% of the time. Also with 2 kids in car seats, heated seats won't do anything for them.
I really don't like the Soul, maybe it was caused by those darn hamster ads, but I would never buy one. Also, 110 miles wouldn't cut it during the winter.
We live in the North East also, VERY Northern NY, 30 miles South of the Canadian border. Where about are you? ALL cars suffer less mpg in extreme cold weather as I'm sure you know, even non hybrids do. I'm confused about your statement "with no electric heat", does the volt have electric heat as opposed to gas/engine heating? We have the 2017 Niro EX, mpg has been great but of course once winter hit and temps went below 30, mpg dropped off the cliff. All 50 states get "winter" and "summer" gas blends that affect everyone in every state, I think "winter" comes out sometime in October, and "summer" comes out in April (we've seen MUCH better mpg's lately with our April gas up............ I added 4 snow tires in October and made a round trip to Lake Placid NY in the Adirondack mountains WITH 4 snow tires on, we we "landed" back at home, we got 50mpg out of that trip, BUT temperatures were in the 50's........... so the snow tires only affected overall mpg a little, not as much as some people say (these were JUST snow tires, NO studs).......... In August, one month after getting the Niro, with the Michelin energy saver tires it came with, we did a 90 mile round trip (mostly all highway, not interstte) and clocked 57.7 mpg.........but I have to admit, SHORT trips in Northeast COLD are a killer on mpg!!! The car has performed excellent however and I have to admit, having been a person who previously over the years had a lot of company provided cars, plus our own, and ours always had snow tires, the NIRO handles the absolute BEST in snow with snow tires, I actually think the regenerative braking has something to do with this also as there has been absolutely NO skidding, NO indication that the ABS ever kicked in, in the past in winter driving we would always hear the ABS kick in at some point during winter driving,,,,,,,,NOT with the NIRO...........I think the use of regenerative braking and less of the old fashioned "pads & rotors" braking has a lot to do with excellent winter stability. The other poster is correct, if you can get away with using the seat heaters that might be enough,,,,,,,,,,,BUT I must admit, once your moving the Niro heats quick and setting the temps at 65-68 is plenty comfortable in the cabin especially with heated seats.......... I've seen the Chevy Volt, like the look (better looking than a Prius!) never been in a Volt..............all I can say is test drive a Niro....... the SOLID feel should impress you, this vehicle feels so much more solid than any I've ever driven.............I highly recommend it!!!
I'm in NH. Probably not quite as cold as you, but we still can see a couple weeks in the negative degrees. And we just woke up to 1" of snow and ice this morning...
The Volt does have electric heat. It's designed to function as a full EV for the first 40 miles or so, which includes all climate controls. Once the temp drops to 15 degrees, the engine will come on periodically though.
I am familiar with all the mpg intricacies, as the Volt is affected quite a bit by them. And as far as snow driving, the Volt handles it extremely well too. The stock tires weren't great, but I put Continental TrueContacts on, and they do great in the winter.