I agree with staehpj1. Especially the part about short days.
I have a built-in sense of how far I can ride in a day - -
that was completely off for winter riding.
You just don't have that many hours of usable daylight.
Three things make short winter days even shorter for cycling.
1. The morning chill makes it hard to start early.
In the Southeast it is bone-chilling damp, in the Southwest it's just, plain cold.
2. Ya gotta eat lunch. I felt guilty about stopping for long.
Lunchtime is usually the best riding weather.
3. Stopping to smell the roses. Or walk under the live oaks.
Most folks want to visit the sights along the way, not just ride nonstop.
Plus, I found a some Southern state park campgrounds "Closed for Winter".
Winter?? I'm from Wyoming. It's only 45F. But they have thin blood down there.
I was used to summer mileage around 75 to 80 miles per day.
But when I tried to do this in the winter it made for a tough trip.
I quickly downscaled the mileage.
I may be a bit weird in that I wound up doing quite long for me mileage on the ST even in the winter.
I found that much of the way there was just so much empty desolate road that I was inclined to knock out long mileage. I did more 90 and 100 mile days than I usually would, but I went in February-March when the days were
much longer than they'd be in December-January and I was not bothered by starting early since I don't mind the cold much. I think the only day where I stayed in for it to warm up was the one night it got down into the teens and stayed cold for the early morning hours. Since I was on top of a pass I didn't relish the cold descent.
Not sure what kind of daily mileage I might have done with the shorter days of Dec-Jan, certainly less than I did when I went in Feb-Mar, but maybe still longish.
Also for me sometimes the summer's long days are offset a bit by my inclination to take more breaks in the heat. So I think I averaged longer days than I typically would even in summer.