I'm not really liking any of the options so far. I'm struggling to come up with a name ATM, its so much easier to come up with names for arts and techniques.
Frostwood does sound better than Meltwater or Confluence to me but I would trust Yrsillar to come up with a name that works, if nothing else shows promise.
Edit: We're gonna call the town Wall Breaking ? That doesnt a little weird?
Ironwood just makes me think of General Ironwood from RWBY lol.
New Spring sounds kinda contradictory for a place that must be pretty chilly this close to the wall lol.
I guess I like Frostwood the best, its appropriate for the name of a border town between a winter fantasy land and a fantasy empire full of greenery.