A layer of smoke in the stairwell sounds implausible to me, in a modern stairwell.
From the fire education classes I've attended, I think my biggest concerns are that a fire door might be too heavy for me to open if there is a lot of smoke outside, and I often stay in lower quality accommodations that may not have as sophisticated fire equipment as the large chains.
I have always at least checked the diagram of where the exits are and the evacuation plan, and carry a small torch, but will now add a visual inspection to my check in routine.
Thanks for bumping this up.