Warm Winter Biking in US

My partner just got a job where he can’t take time off May through August. We live in the upper Midwest, so that is generally when we did all of our local bike touring trips. Now we are going to have to figure out how to fit in some trips outside of that season.

We can still do trips in the Midwest in September, since we basically always have hot and warm Septembers now. But for the rest of the year it starts to get quite cold at night, like a layer of ice on your tent when you wake up. That kind of camping is fine for a night or two, but I find it difficult to handle for a week straight.

With the exception of the south (for many reasons) where do people tour outside of summer? Do you tour in the southwest and just take lots of highways? Do you try and bike around the Pacific Northwest in the fall before it gets rainy and cold?