I've done one short two-day tour that was originally considered a test run for longer tours not yet done. My touring bike had only previously been ridden with one or two paniers for bicycle commuting to work. I drove four hours to my starting point, loaded up my bike with the four paniers and handlebar bag (about 50 pounds), tent bag on my rear rack and a 25 pound dog trailer with a 75 pound dog. That's my 200 pounds with an extra 50 pounds on the bike and 100 pounds behind me.
As I mounted my bike, the only thing I could think of was the fear of possibly not being able to move all this mass. I remember saying out loud, "Perhaps I should have tested this at home." The dog and I had a good two-day trip. I don't think I went over 13 mph, but it was fun.