I think it is doable on one map, even though I did snow trophies on separate city. Just make sure you buy land with every kind of source (oil, ore, fertile, forest), have random disasters at max as soon as possible (idealy from start), same for day/night cycle. And be careful with money. Snow maps are little harder at start cause heating needs lot of electricity.
EDIT: I forgot... There are 3 mass transit scenarios you must complete, so theese are not technicaly possible doable on your main map. And you need to win/loose 5 scenarios. Loosing is easy. Just wipe city if loosing condition is not to get under certain amount population. For win, you can save almost won scenario and win then reload it five times.