Good timing on your part Poor Behavior. The good news is that here in Alabama we get to ride all year!
The last two weeks have been pretty cold with the highs only reaching the low 30's. Next week however, we are going to be in the 50's for highs. Probably be close to freezing at night and early morning. Rain is projected for this Saturday and ending on Sunday, so the riding should be good for the rest of the week following.
The closest trail to McClellan would be
Iron Legs. It is right there at the base. There is also a trail at Cheaha state park. I've not ridden those myself so maybe someone else will chime in with info.
Don't miss Oak Mountain in B'Ham. It has 18 miles of trail and is well maintained by
BUMP. The park is only open until sundown except on Wednesdays they are staying open until 9:00 PM for nightriding led by Cahaba Cycles and BUMP. Be there by about 5:30 if you want to join in the group ride.
There is also 5 miles of trail at the Trussville Sports Complex. It's a fun ride and you can ride it any night up until 11:00 PM when the park closes. It's probably about 20 miles closer to you than Oak Mountain.
Down in Sylacauga there is 15 miles of trail called
Sylaward around Lake Howard and in Tuscaloosa (maybe too far) there is
Lake Lurleen with 15 miles of trail.