My wife and I have done quite a bit of touring on our road bikes. I made custom tapered panniers to prevent heal strike. We did not do any epic rides, but the bike equipped with 28 mm tires, did a good job hauling us and our camping gear on 2- week rides. I think they would have handled longer trips, but we were working at the time and our tours were relatively short. Both of our bikes had aluminum frames, and my wife's bike had a carbon fork. Depending on the route, I believe that the Raleigh would do fine. We both used our stock 9 speed chainrings, but replaced the rear cassette with an 11-34. We also replaced the rear derailleur with Shimano LX mountain bike derailleurs. We thought we died and went to heaven when we got 9 speed triples with a "small" 30 tooth chainring.
A better look at my wife's bike. It is the same model of bike as the one in the picture above. It is just a new frame.
Touring on a stock Peugeot PX10--1100+ miles in 11 days. The tubular wheels were traded for a set of clinchers that I used for training. The panniers are the first pair I made in the early 70s. I did a lot of tours on this setup, 14-28 5 cog freewheel and 45/53 chainrings.