I always store my car during the winter in the garage. I always ensure that all the fluids or changed prior to the storage. As for the gas it is best to store the tank FULL with a fresh tank of gas. The reason behind this are:
1) Safety: the fumes in the tank are explosive, less air space = less fumes
2) Less air space = less corrosion possibilty.
3) More gas the longer it will take for it to break down.
These may not be the best reasons for storing a car with a full tank, but it make sense.
Just my 2 cents. Enjoy you trip
2003 SLK230 (Sport - 6spd)
1995 Ford Thunderbird