I do a lot of travel as a geology consultant now 5. I used to just pack a couple of bodylastics system handles, and a few black, red and green resistance bands in my hand luggage. That way even in your hotel room you can at least train. You get a couple of funny looks at airport security put worth it.

This is a great video BTW, def been to a few hotels where I've been told there was a gym, walked in and been like ahhh. Same with some mine sites.

For anyone interested in a throw in the bag kit, consider the bodylastic bands, fairly cheap on Amazon. I got their MMA training kit, but I see they have improved it slightly in the 5 years I've had it:

https://www.amazon.co.uk/Bodylastics-Resistance-RESISTANCE-components-instructions/dp/B002U51JV2/ref=sr_1_5?s=fitness&ie=UTF8&qid=1515779406&sr=1-5&keywords=bodylastics