I am suspect of how those palms in Montreal are cared for, I would not be surprised if many of them are stored in hot houses during the winter or are wrapped up so much you can't even tell a palm is there in the winter.
Essentially because below -11 all the palm reproductive organs are killed. Most of them, if left exposed, will die completely between temps of -15 to -20.
So they can be present in decently cold winter climates, but they will be far more prolific and healthier in climates such as Vancouver and Victoria.
Around White Rock, south Van, parts of the Sunshine Coast, the Victoria area, and the gulf Islands self distributed palms (escapes) have been found. Usually these escapes are found in neighboring yards. What seems to be a really hard grass starts to pop up but it is actually a baby palm.
So yes, there are windmill palms in other parts of Canada, but the BC coast is the only place they can be gown with little to no care (even neglected ones will survive just fine)
And for the record, they grow in Abbotsford just fine. They are in Agassiz as well. Hope is more of the barrier in the Fraser Valley.
Victoria can grow a couple varieties of palms, including a few Washington Palms.
This is pic I always love of the Victoria city hall. In Victoria the palm trees can actually reach true palm tree sizes.
http://vibrantvictoria.ca/local-news...y-hall-levees/
Wish there was a better pic of this.
And some of my own:
Victoria:
Gardens in Vancouver (you can see the barries)
Near English Bay
Close up of the berries (this palm is on Robson street)
Now these are in Tofino, and they can't grow anywhere else in Canada. They grow like weeds on the west coast of Vancouver Island and on the Gulf Islands. In metro Vancouver they are stunted and can only really survive right next to the ocean (Downtown / White Rock). Easter suburbs, nope.
Pics are my own.