I would structure it this way:
18 Days at home:
3 on, 1 off, 3 day split (E.g. Legs, Push, Pull)
Program focusing on high intensity, lower volume (this will depend on you and how you've trained in the past - it might be more volume oriented). I would basically train so that by the end of the 18 days, you are nearly overtrained ("overreaching" is the term often used) - not quite - but your gains would be slowing soon. Eat like a monster, lots of rest.
18 Days on the Road:
1 on, 2 off, a 2 day split.
Take the first week and take it easy. You will benefit from adapting to what you did during the 18 days at home. Maybe no training for 3-4 days, then first two training sessions (1 on, two off), train about 75%.
Thereafter, FIND A WAY to train hard, 1 on, 2 off with a 2 day split (upper and lower or Push and Pull) DC style training or how Phil trains would be a great choice. (Would also be a great choice above, but I'm not sure what you do now / what works for you.)
Feel free to take it easy during the last 3-4 days on the road, as you'll be home soon and ready to start the next 18 day period of kickin' ass.
The days on the road, you're basically trying to get a small overreaching effect and then maintain your strength / size until you can train, eat and rest properly again at home.
Just one idea. There are other ways, too. 8^)
-Randy