My grandfather on the east coast went down to his pond and pulled out a bunch of pond weeds and sent them to me. They had been living in a harsh snow/heat shift for 50 years. I cleaned them off and was using them outside, but I have some in my aquariums now. They're fine.
The only thing is, he got them from a pet store in like 1743 and the owner wanted him to farm them in the large ponds on his farm... They're likely tropicals.
I'm sure local plants can take warmer temperatures, at least for 4-5 years, before they die. That is if they require DORMANCY. If you find them in winter, they'll be fine.