It's about sixty miles, or nearly an hour, from Valdosta to Lake City. That's not unreasonable, but it is more than just a quick run across the border, and when you have already been on the road 8-12 hours, it makes a difference.
I have been known to stop in Lake City on the way back north, though, with the opportunity to stay one more night in Florida at least incidentally influencing my decision to stop.