I decided long ago that I could buy a lot of 4x5 film for the price of a 6x12 (or other) rollfilm holder and simply crop when I wanted a panorama view.
This has several advantages: 1. I can develop each sheet optimally, not at an average development for an entire roll. 2. I don't have to lug an extra, heavier holder around. 3. I can use different aspect ratios easily just by cropping. 4. I don't have to wait until the entire roll is exposed before seeing results. 5. I don't need different storage systems, extra developing tanks, reels, negative holders for the enlarger, etc. (again, more expense that could be better invested in film). 6. I don't have to change rolls in the field. 7. For a lightweight field camera like you (and I) use, rollfilm holders are often impractical due to weight and thickness. Plus, they defeat the goal of keeping things lightweight. 8. The list goes on...
The only downside I can see is if the film you like is not available in 4x5.
Just my opinion, but, I hope, helpful.