I never was able to get back to you but I hope your trip went/is going well. I just got back from my last business trip of the year and I was pretty surprised that stepping on the scale today I was only 171lbs (GREAT because TOM started today so being up 2lbs is just about right), plus I even am finally down another 1" on my waist
so it can be done. Mostly I tried ot get veggies when possible and really listen to my body in terms of fullness when I wasn't.
Oh, and I made an exercise routine (just about 20 min) that I did in the hotel room that avoided using my knee (if you're interested in it let me know). I also tried to make sure to walk/take the stairs when possible. I know those things don't make a huge difference but they help.
In terms of dieting, I think it's a pretty wise idea to plan on maintaining over business trips. Then if you do lose weight it'S GREAT but if not you're not stressing out over the extra sodium etc. Plus it's normally a great way to practice for the future.
Anyways, good luck with everything!