I have had jobs in which I traveled a lot, at least 50% of the time. It is certainly doable, and you need to prepare your systems for that kind of work.
What helped me most was email, mobile phone, skype, and a good international calling card.
The basic GTD system works well, but I went a little more to paper-based during periods of peak travel. Just my preference to deal with cranky computers, dead batteries, etc.
I also found it worthwhile to buy an airport lounge access card (priority pass). Working in a lounge is much more productive than in the general airport waiting area.