First frost is coming soon. Too late to cut comfrey one final time or is it okay?

I live in the mountains of Virginia, and we are likely going to have our first frost in about 2-3 weeksish. I have comfrey growing, and it is its first season in the ground. It currently doesn’t have any flowers, but lots and lots and lots of leaves, very bushy. Part of me wants to cut it back to the ground and use them for one final mulching, but I’m concerned frost is coming soon and it’s still it’s first season growing. Should I leave all of the leaves on? Or, can I harvest them one last time?