You can tour on anything...
I do shorter light loaded tours on a 40 year old Raleigh 3 speed. I have a 41 year old Raleigh 3 speed that I have had for over 30 years that still hauls loads home from the grocery store, it was a daily rider for 7+ years. I also don't mind walking up steeper hills.
Depending on the terrain, your strength and the amount of weight you plan to haul you possibly can do it. Moving weight to the front on a tour bike is usually a good idea anyway to get some of the weight off the rear wheel, which is already taking the bulk of the load.
Aaron
