Our '09 GT378TS doesn't have an LP port and I never saw it as an option. I don't believe they are hard to add though. It does have a TV feed and outlet in the compartment right aft of the entry door though so if you want to have your TV outside you can do that.
Congrats on the new rig, we took delivery of ours this last September and the maiden voyage was from our home in Washington to Arizona, back through Moab, UT for some Jeepn' and home, a 3 week trip with no problems. We are extremely happy with ours.