There are tons of all bodyweight excercises that you could throw together in a circuit fashion in your bedroom. I've always thought that if you're creative enough, not having weights is no reason to lose progress, as I've gone through some bodyweight circuits that have almost made me puke.
Here's a few good bodyweight excercises:
-bodyweight squats (a ton of them, probably fast and maybe in a breather squat fashion)
-Overhead squats (doesn't have to have a lot of weight, just holding anything over your head will be a chore just to maintain the posture for a lot of reps)
-Single leg squats
-lunges (regular, bulgarian off a chair or bed)
-wall sits at varying depths
-All manner of squat, lunge, tuck, or scissor jumps (if you can jump around in your room)
-Standing Bodyweight Goodmornings
-Single-leg King Deadlifts
-pushups (regular, incline, clapping, hands close together, Hindu)
-Handstand pushups (balanced against a wall probably)
-Lying Leg L's (lying on your back, legs straight up, then rotate side to side)
-Front, Side and Back bridges with single leg raises (bridge resting on elbows and/or hands)
-All variations of crunches.
You can string some combination of these together in a circuit fashion doing 10-20 reps of each, going through the circuit like three times and I guarentee you won't have to worry about losing ground while you're out of the country. You might have to worry about losing your stomach contents though, if you do these with little enough rest.