You didn't list your iternary but since you appear to be located in PA I would suggest that you shop on your way to Lander. Lots of towns in the west have "western wear" stores and quite a few have hatmakers in them also, the custom hatmakers usually have some pre-made or that for some reason the customer who ordered them did not like the hat and quite often these can be purchased a significant discount.
It has been quite a few years since I have been through Cheyenne but on the main drag near the old railway station there were a couple of large western stores across catty-corner from each other and both always had a big selection of hats and boots.
Don't do a little googling and see what hatmakers/western stores pop up along your route.
drover
p.s. - I would think that there is a good chance of finding something in Lander.
It has been quite a few years since I have been through Cheyenne but on the main drag near the old railway station there were a couple of large western stores across catty-corner from each other and both always had a big selection of hats and boots.
Don't do a little googling and see what hatmakers/western stores pop up along your route.
drover
p.s. - I would think that there is a good chance of finding something in Lander.