I have used lightweight road bikes to tour over the past 40 years, I wouldn't recommend it, even with a steel bike and 25mm tires. It can be done, I've done it, but it's a more enjoyable experience with a heavier bike and larger tires. You will have fewer problems and be more comfortable. If you do use the road bike, I'd suggest a trailer. Keep the extra weight off the bike, it really wasn't designed for that.
Marc