Have you considered Calgary?

Calgary will technically be the cheapest place to live that ticks all those boxes. The city was high on the oil price hog for a long time and has consequently been in an economic depression since, what, 2015 I think it was - you're definitely not going to accidentally fall into a $100k/yr job with an oil company any more, but anecdotally at least the 'normal' economy doesn't seem much worse off than anywhere else. It's a very physically large, low-density, spread out kind of city with on the whole a very large-C Conservative population which may or may not bother or impact you depending on the sort of person you are and what you're looking to do with yourself. Public transport exists, it's honestly pretty good taking into account the stupid scale of the place but there are necessarily areas that just don't have enough people to justify running more than a handful of buses a day etc. I personally don't like the city and find it ugly and aggressive about a lot of things but YMMV and plenty of people do.

IMO the big upside to Calgary is that with all the oil company HQs etc there's still a quite healthy, busy downtown area rather than having all those businesses run off to suburbia. So, transport's still mostly focused around getting you into the city, therefore can function pretty well, and it's a place where you'll be surrounded by normal people rather than meth-addled lunatics.

Vancouver is still a magnet for travelers despite on the face of it being expensive, reason being that although due to the price of land it's a horrifyingly expensive place to live the bougie dream (big detached house, big garden, 2.4 kids and a dog sort of thing) it's not as bad if you're going to be renting, and it's particularly not as bad if you're going to be renting rooms in a house and dossing around at the ski hill all day as there are a lot of "investment properties" let out for less than you'd expect. The real problem is not cost per se, it's that the rental vacancy rate is so low that you have to at least consider the possibility that you'll be living in a youth hostel, or the converted minivan camper you just bought, for a little while before you find somewhere to settle down. Oh yeah, did I mention the converted minivan campers? There's an awful lot of people living in vans in Van-couver, but it's also ground zero for people starting and ending massive roadtrip holidays, so if that's something you're interested in doing it's probably the best place in North America to find a vehicle for it (search for 'France' or 'Germany' on Craigslist car ads for the full experience)

I wouldn't personally move to the Okanagan (so Vernon, Kelowna, Penticton etc) if you're at risk of working any sort of service industry job - yes, great places to be if after the boat in the morning/ski in the evening type of life, but they're to a great degree sunshine/retirement getaway destinations for Albertans as the summers are generally long and dry and the winters short-ish and dry-ish. End result is you'd have lots of leathery, entitled old shitheads to deal with at work - think Costa Del Sol with worse weather and more lifted pickup trucks - and you'll tend to be paid less than you would elsewhere as so many people move there for the 'lifestyle'. You run into a lot of them here in Golden as they stop over briefly on their way to 'our cabin in the Okanagan...' and the thought of having to put up with them for longer than it takes to get out of the supermarket queue makes my skin crawl. But, again, that's me! Maybe you have a thing for racist grandpas, heh.