I've put 26,000 miles on my Wide Glide in 4 years. Not outstanding numbers but, living in Minnesota, it sits covered in the garage for at least 4 months each year. I'm 56 so I'm no spring chicken.
Longest ride in one day was 700 miles. Many 4-500 mile days in the saddle (corbin dual tourer, sometimes with an Air Hawk cushion). Several 2,000+ mile trips. I've set the bike up to be as good a tourer as a Wide Glide can be. Corbin seat, nice saddle bags, highway pegs, tunes in the helmet, GPS on an iPad in the tank bag.
I ride with guys that ride Road Kings, Valkyries, & BMW's. when they ride my bike, they say they don't know how I do it. I do it because I love my Wide Glide. Someday I may go to a tourer, hell, someday I may go to a trike. I've ridden the BMW 1600 twice and it would be tough to find a nicer all out touring machine than that. Haven't ridden a Road Glide yet. Don't really want to because I don't want to become dissatisfied with my Wide Glide.
Is a Wide Glide or a Springer or a Deuce as nice to tour on as a Road Glide or an Ultra, no it is not. But you can ride thousands of miles on a "bar hopper" if you want to and have just as good a time as anyone on a touring machine.
Get the bike you want and can afford. Make a smart purchase of a nicely maintained used bike (preferably from the owner and not a dealer) and save some money. That way, you won't loose a truckload of cash if you want to trade out. You can always trade for something else if you decide differently down the road.