We have an REI Kingdom 6. Because it has a floor, we always take 1/2" blocking to put the legs on. You really need this anyway in order the level the bunk. Take a bunch of 2x6 blocking or precut a big block to lift one cot higher than the other and overlap the frames. If you are only looking for a couple inches, it will make all the difference.
When We flew in this year, I ditched my oversize cot, and only took the foam bed roll. I slept really well on that, but you lose all that storage space that comes with a cot. I will likely get a smaller cot so I can be less of a tent hog.