Hi! We're new to camping...Bought a 2013 Shasta Revere this past fall, and we've been on 3 trips. Disney will be trip number 4! How do we gauge how much propane we have? Besides running out LOL...We are going to fill the tanks before Disney, which will be a 2 week trek for us, but we have no idea how much cooking or even using the heater this past fall and this weekend uses! If anyone could give us an idea, we'd appreciate it! Thanks!!!