Right, so maybe understand why they may feel a bit xenophobic. Beyond that, the old gray mare that told Bran stories in Season 1 said that these were all legends that could never come true. But sure, these northern farmers should instantly have a change of mind when they're told that the things they've been hearing are ghost stories are actually true.
Fun Fact: I've had three buddies who woke up in a tub of ice who had their kidneys taken from them.
Quit being so fucking literal about a fantasy.
There really wasn't resentment made of the dothraki and the Unsullied armies though. Not in the last episode. All the resentment was targetted at Dany, and the fact she was a Targaryan, and the daughter of the Mad King.
Targaryan's are not a recent development in Westeros, they had been under Targaryan rule for 300 years. And for the vast majority of those 300 years, the North did really well. yes there were plenty of wars and squabbles during those 300 years, but the North stayed out of them leading up to the mad king. Claiming Dany is a foreign invader is tenuous at best, she was born in Westeros. her exile was not the result of anything she did personally either.
this leaves us with just the fact she is the daughter of the mad king. So what? Still compares rather favorably to Cersei, and sooner or later they will have to support one of them, or have you not been paying attention? Jon has already made the point that he doesn't consider the children to be beholding to the actions of their parents (Umbers/Karstarks).
Not saying they shouldn't be aware of the past, but rather they have formulated an opinion before they have ever met the girl, who buy the way just happens to be up there to save their ass.