Ah, so mine always has two plastic bags over it when parked up outdoors, I know I'm cheap. Between saddle pack and mudguards the rain really doesn't hit it much when riding. I'd think left in the rain for 5 minutes would give it more moisture than 2 hours of riding. Don't forget that it copes fine with all the sweat from normal riding. Remolding is feasible so is lacing the sides, I'd need to see it. I think you can also send it back to be revitalised but am sure there would be a charge.
If you really don't fancy tackling it I'll give it a go. Maybe not a soaking, from what you've described I'd have thought a small amount of softening oil could do it. What about the seating area, has the leather wrinkled/bunched up or is it still pretty smooth?