Anyone done a tour on a SS/FG?

I've got a bike that i'm setting up for touring that has a single speed drivetrain, which needs a rebuild. The question is, freewheel or fixed? The freewheel would help when tired or when going down long hills/gradients, but fixed could help with cadence and hillclimbing from what I understand.

Also, there's the question of gearing, which could also vary depending on whether it's ss or fixed. My road gearing is about 70 gear inches, and my off-road/bad weather gearing is ideally about 55. What's a reasonable medium to adjust for long distances on the road, but likely minor forays into bad weather, light offroad, etc? I've heard a 10% reduction from road gearing works best but I'm not sure.