Tell us gregw, how do you really feel?
Try a short weekend tour when things warm up (it it's cold where you are now) and see how you like it. I don't mind riding fixed around town, and I sometimes do circular loops around town... I think I've done around 50km but it's not super-hilly here, and I wasn't loaded... but if you're young and in decent shape, plan your route ahead of time so you know what kind of hills you're facing, I think it could be doable. I've seen some setup with two chainrings at the front, and a flip-flop hub with different gears for hilly terrain and flats. It seems like a bit of a pain to stop and change out the chainrings and lengthen/shorten the chain with something like that, but it's another option to consider.
I know hating on fixie riding is kind of "the new black" or whatever, but if you want to try it go for it, I say. Do you have any previous touring experience?