Clothing for offwidths in the alpine

TL;DR: What alpine-friendly clothes also work well in offwidths?

Full version: I love cotton for wide climbing -- I feel much stronger in offwidths when I'm wearing jeans and a long sleeve cotton shirt, as I seem to get a lot more friction against the rock. I admit that some of that may be psychological, but when I climb a route back to back with my cotton getup followed by synthetics (rock/alpine guide pants and a capiline 1/2 shirt), I feel there's a significant difference, so much so that I recently did an alpine route with a significant offwidth wearing all cotton to maximize my chances of getting the send.

But this isn't the best long term solution; we did it car-to-car on a day with ideal weather. So, any suggestions on something that might work better than what I'm currently using but is still appropriate in the alpine?

Thanks in advance for any input!

For the widest of cracks may I recommend renting a set of these for you and your belayer.