I rode 70 miles roundtrip last Friday. Me and my cousin went to the beach. I was carrying 12 lbs. on my 24 lb. 'cross bike. I had my backpack strapped to the rear rack. I also had (3) 24 oz. water bottles on the frame. My gearing was a 1x9 setup. It consisted of a 36T chainring and a 12-26T cassette. The gearing was perfect for the hills and flats.
I was sore on the way back. The weather was around 95 degrees. I found out what I needed to adjust and replace on my bike. It being a stock 'cross bike, it wasn't setup for a trip like that. But I did make it without walking the bike.
I am yet to go on a official tour. You guys/gals must be in tip-top shape to ride for long distances carrying all that weight. Whether it be light-touring to full on heavy loads. I guess I'm trying to say that I'm out-of-shape. I've ridden long distances before, but no 70 miles. I never thought about giving up. I enjoyed every minute of it.
Whether it be a weekend tour, 1 month or a whole year, you have to be in great shape to do it. And that is why I salute you.