Requirement of both inlet and outlet depends on quite a few things.
In Europe - homes heated by natural/earth gas central heater (sometimes also provides hot water) usually require “mechanical ventilation” - which is just a box with efficient fan that’s always running and exhausting at least a little bit of indoor air, and you crank it up when cooking/showering/etc, as well as some form of grill/grate/opening to let outside air in.
It’s not only because of using gas for cooking/heating - officially it’s also to make sure your house doesn’t build up too much of things like Argon that’s creeping in from your crawl space/basement/etc.
For example Velux slanted ceiling/roof windows have that ventilation option built in where you can close/lock the window, but still allow fresh air (and no bugs/mosquitos) in.
Otherwise it’s either some sort of ventilation grill on your windows/doors, beeing able to slightly tilt/crank some windows, cutout/opening for mail in your front door…
Or any other place where your house is not hermetically sealed :)
TL;DR: No - I think across the Europe 19° to 21° is common during winter. Less than 19° if you’re trying to save money and have old house (and here homes might actually go decades if not centuries older) with crap isolation; and maybe up to 22° if you have kids/baby and have good isolation.
The majority of Dutch keep it at ~19° during winter because of cost of gas/electricity. And then so far majority kind of hoped global warming isn’t a thing. So during summers 25-30° (if not higher) also started to be a thing inside homes for those folks that don’t have airco and have computer on their attic/zolder. And that’s with shades/roll-blinds mostly down yet windows are open 24/7 so it circulates and cools off during night …etc.
These days (actually almost last decade or so) the “joke” is that getting a house just about anywhere in The Netherlands is great investment because within just a few decades you’ll [likely] have a tropical house next to a beach.
No wonder that pre-teenager kids need to pass a swimming lessons/certificate where test is basically “clothes and footwear” (they allow thinner jacket & sweater, borderline pajamas for pants and I guess no need for “Canadian Boots” and sneakers are fine) - where you’re pushed with your back into the pool, and then you need to swim under some obstacles (floating platform), and through some hole in a plane/flag, and pull yourself out of the pool.
BTW I’m originally from Balkans - Belgrade/Serbia where “European continental” climate is, or at least was a thing when I was growing up. I would think Toronto and New York are very similar.
So at least 30° Celsius outside during summer (now regularly even more and sometimes closer or above the 40°C), and quite a few weeks/years where in just a few hours we went from 0cm to 50cm or more of snow, causing total transport collapse - which meant no school ;)
Anyway biggest issue for me during summer here in Amsterdam/NL (which is still below summer heat I grew up with in Belgrade/Serbia in terms of ° Celsius) - is the humidity.
Calculation/story wife and I (and family that came to visit us for extended period here in NL) have is basically:
- around 0°C and the Dutch are hopeless. I mean country is flat, yet cars and even trucks/lorries get stuck - obviously because many use summer tires, though also they just don’t know what to do (e.g. shovel, sand/salt, rubber floor-mat) even when they have all-season/universal tires that people can go to mountain without snow chains
- 10°C or less outside might require a bit thicker pullover/sweater or even windbreaker jacket, and if it’s <=5°, windy and sun isn’t strong enough - I might feel like Timberland Pro, North Face parka jacket
- And yet 25°C or more outside might require you to wear short pants, t-shirt, flip-flops and hide from the sun or else you might get a heat stroke