I have a kegorator that I built into a counter at the family camp. The beer line comes out the top, then snakes around a bit in a wall before heading up a tower. I think it's about a 3' uninsulated. It's not used all that frequently, so all I do is pour out a little bit (~4oz) at the start of a drinking day and it's usually good to go. I also use some faucet plugs to help keep the faucets clean. That way no microbes can work their way back. I'm rather lazy about the lines and clean them at the beginning and end of the season.
I wouldn't worry about the 8". Just pour a drop for your homies and your lines will be good. Insulating will help some but not a whole lot.