I'ts up to you. Some roses can stand no spray conditions better than others. The antiques are much better in their disease resistance in that regard. I think you'll find if you're growing modern roses, that you'll either have to spray regularly, or you'll have to dig them up, or you'll have to tolerate naked sticks that don't overwinter very well even in a mild climate.

What do you value? Spraying properly every week with a respirator and long pants and long sleeves and gloves and a hat is a hassle and just isn't worth it to most folks who frequent this forum. They'd rather grow the roses that grow well for them with the amount of care they are willing to give, so they cull the sticks and move on. There are lots of choices out there in your climate zone for roses that don't have to be sprayed.

But, if you view roses as only the modern high centered hybrid teas, then you'd better be prepared to pamper them, including regular spray, if you want to grow them well. There's no point in growing roses that don't really suit your climate well and growing them badly just because you refuse to give them what they need to survive.