Well, according to locals in Ennis, the first thing Californians try to do when the move to Montana is implement THEIR lifestyles on Montanans. Everything from cocktails to politics. (I used to have bumper sticker that said "We don't give a DAMN HOW they do it in California", which was from a bar where the bartendars got tired of hearing Californians complain about the way drinks were made at that bar, mind you, this was a hunting/fishing town where alot of out of towners come in ...)
The other problem is...alot of Californian developers with tons of cash come up and buy up large tracts of land and develope it, Californian-style, with 6 feet between the houses and 100 ft. high "privacy fences" ...then they advertise these places in California, and guess what? You have mass migration of retired Californians moving in trying to "change Montana".
But you're right, as long as you adapt to them, and not expect them to adapt to you, you'll be fine.