Well....if you have truly large and STURDY trees, a couple of once-blooming possibilities are the 'Kiftsgate' hybrids 'Treasure Trove' and 'Brenda Colvin'. Both are fine roses, fragrant and enormous. I don't know how they would do for you: I grow them and like them, but my conditions are different from yours. Actually, also there's 'Kiftsgate' itself, famous for its size.

Another possibility is the Noisette roses. For example, 'Jaune Desprez', fragrant, and, according to HMF, hardy in your zone, though that doesn't mean it would grow well. It has a floating fragrance, very nice. It's a pretty rose but wickedly thorny. Also 'Mme. Alfred Carrière', which gets huge, is a tough variety, and is wonderfully fragrant as well as having lovely flowers to cut. Both of these are reblooming. They get some disease but aren't bothered by it. I don't know how they'd do in your conditions.

Another group to consider might be musk roses: for example R. brunonii and its hybrid 'La Mortola'. Both are once flowering, thorny, and huge. Fragrant, naturally. In my opinion a large sturdy tree is exactly where roses like these belong, as 'La Mortola' at least is quite painful to train and prune. Send it up an oak and let it romp, is my suggestion. Whether it will thrive in your climate I don't know.

There are smaller roses that can climb if given support: I don't know whether they'd interest you. The hybrid musk 'Vanity', a long and lanky plant, can get quite a good size with support; I've also see 'Cornelia' as a respectable restrained climber. Both of these are fragrant, and the fragrance wafts. In my opinion 'Cornelia' has a particularly lovely scent. These are somewhat reblooming, tending in my climate to focus on spring and fall.

There are, of course, those classics 'New Dawn' and its more double sport 'Awakening', and these are cold hardy, as well as everything else hardy, too. Moderate apple fragrance. I'm particularly fond of 'Awakening'. These are repeat blooming, thorny, get some disease but it doesn't matter. You might look into other ramblers bred by Dr. Van Fleet, as he was from close to your part of the country and bred for cold hardiness as well as beauty, and many of his roses are fragrant.

And finally--I think--there's the lovely 'Mme. Plantier', once flowering, divinely fragrant. I've mostly seen it as a large shrub, but I think that with support it would climb. Few thorns, cold hardy, tolerant. It does have the fault of the old blooms hanging on to the bush, but still, what a marvel.