I went through a spell of trying various tea roses in zone 5 Nebraska for the fun of the zone pushing. I had about 5 teas that I was able to carry through a couple of winters in a protected south side of my house, virtual zone 6 temperatures. I protected with filled leaf bags stacked around the outside of the plants as a windbreak and temperature moderator. I killed way more teas than survived even briefly and I wouldn't try the experiment again these days.
I echo the feedback here that teas really aren't made for cold zones. Apparently they don't ever quite go dormant even in the worst of temperatures and that makes them vulnerable to winter kill. They also dislike pruning and that just has to happen for roses in my climate.
Of the 5 roses I overwintered for at least 2-3 seasons, I only have one left (Maman Cochet). She's about 9 years old now but is NEVER bigger than knee high. She has a few scattered blooms here and there but is perpetually just on the brink of survival. The ones that lasted a few winters were Mrs. BR Cant, Georgetown Tea, Duchesse de Brabant, and another one I've forgotten. A friend in town who grows MASSIVE HT roses (e.g. his Lady of Shalott is an absolutely HUGE climber) gave me a pass-along Mrs. Dudley Cross that's about knee high and sickly. If he can't grow them here, I doubt anyone could do better.
To my regret, a lot of fabulous other roses that are bred from teas also aren't very hardy in my zone, so I make a habit of checking heritage of roses I'm unfamiliar with. Many Hybrid Teas are listed as zone 7 but can do fine here once thoroughly established if they do indeed go fully dormant. Ample rain and good snow cover also help hardiness a LOT. Teas, not so. I don't think you can manipulate the environment in zone 5 enough to make them happy outside of greenhouses.
And believe me, I've tried.
Cynthia
Q