Over on ZenHabits, Leo Babauta gives five tipos on "How to Keep Habits Going During Travel." All are good. I especially like this one:
Try to do the minimum. Keeping with your flexible mind: if you normally exercise for 30 minutes, try 5-10 if you’re pressed for time or low on energy. If you normally meditate for 20 minutes, try 2 or 5 minutes. It’s better to keep it going with the minimum, than to only do it if you have the time/energy for the full session.