Bad news for anyone wanting to hike the trail in the winter. Talked with the staff at Gambrill State Park. Their response follows:

Thank you for checking in with us regarding the Catoctin Trail. Unfortunately camping is prohibited anywhere along the trail and all of the campgrounds are closed for the winter.

I would recommend waiting until April when the campgrounds open back up. Either that or hiking it in pieces. I know this isn’t the answer you were looking for, but I hope you understand our goal of balancing these wonderful natural and recreational resources.