I chose the latter, because I'm good at waiting (I always bring 2 or 3 things to do on plane trips to the States, for example). In this case, I decided to take Tobias Buckell's advice and write on paper. I took out my old moleskine, given to me by a friend like 4 years ago. I've done lots of brainstorming and pseudo-outlining in the notebook before, but never actual writing. That is, I've never written anything in the notebook that I transferred directly to my manuscript. Tobias followed his own advice and shared his experience, so I thought I might as well do the same.
I also didn't like being away from my notes (my timelines, my outlines, my character bibles, my maps...). I'm a planner, which means I have faith that my outlines are pretty decent to start with - there's a reason I plan. As I spent time writing without my notes, I felt like I was getting farther and farther off my plan.
There was one really good thing about it: it forced me to keep going. There was no e-mail to distract me, no World Doc to write sudden world-building thoughts in, no dictionary or thesaurus to ache over word choice. No notes meant I didn't spend time hunting down details, so when the protagonist referenced something that happened "4 years ago," I had to write "X years ago" and move on.
One of the things that forced me to keep going surprised me: there was no room to edit. Often when I get stuck on something (even if only for a few minutes), I end up looking back and revising. But writing single-spaced in the notebook, there was only a small amount of room to edit. Once I'd changed a word once or twice, there was no more room to change it, and I was forced to leave it and move on.
In the end, I wrote 1,000 words in 1-2 hours. That's about the same speed as my normal rate (although I still had to retype the whole thing once I got home). I'd definitely do it again, if given the opportunity, but I think I'd have to study my notes ahead of time to make sure I stayed on track.
Maybe the next time I fly to the States, I'll bring my notebook instead of my laptop. It's easier to carry around and setup anyway (especially with 2-year-olds in the next seat).