I haven't toured fixed, but many have. Some fixed gear tourers even bring what might be considered a large load (either racks&panniers, or pulling a trailer, or both).
For "hilly" areas a "multispeed" fixed gear setup may be usefull for ones knees. Something along the lines of a
Rivendell Quickbeam, yet fixed rather than freewheel, if that's your inclination. I don't think double fixed hubs exist (for 2 sprockets on each side), so I'd assume one would have to mangle Rivendells double freewheel hub with some type of suicide setup.