Brompton owners

I am still in two minds about the gears. Apart from commuting I have this crazy plan to do a few trips around Europe over the summer, and I was thinking to do some sections of the trip on the bike. I was about to build up a tourer, but now I'm thinking maybe I can pull off 30-50 miles stretches on the Brompton. So what do you guys reckon 6 gears or 2? I have only tested the 2 speed model so far, need to find a S6L.

How much stuff would you need to take with you and over what sort of terrain?