We really like our Disc-O-Bed Cam-O-Cot bunkbed cot. Here is a pic of it in our QF6 (refresh page if image not shown below):
400-lb. capacity per level. My son and I are both 6'5" and it fits us OK. He sometimes wishes for an extra inch, but I don't.
We got a size L to preserve more floor space, but you could do the XL. They make a footpad set to go on the bottom, which helps keep it from sinking into the snow/ice. I also recommend the post extensions to get a little extra room between the levels.
I have a Slumberjack Big Cot that I use when going camping without a partner, but I haven't used it in the winter. It is a great cot I don't think you will be sorry. I have used it for a long time, like 10-15 years.
We have a great camping-on-the-ice thread going. When you make it out camping on the ice, it would be great to get some input from you there.
https://www.iceshanty.com/ice_fishing/index.php?topic=325954.180