Old, I can't speak to how the distances that you view photos at but I think you might be surprised just how regularly most people do.
When I had my studio it was interesting to see people adjust to the size of their photos. 8x10s elbows bent a bit, 5x7s bent more, wallets bent tight, 16x20 elbows straight and locked or starting to step back.
In our homes the hallways and furniture and entrances and other whatnot also regularly define our viewing distances. 8x10s behind a couch regularly get people leaning forward to see the subject matter.
This is part of the magic of standing where the photo is naturally going to be viewed from, with a placeholder where it will hang and figuring out what lens and if that size print will work. It allows you to see if the viewer will be comfortable viewing it from there.
Personally I find that when a print is hung behind a couch, the subject matter needs to be printed larger to keep viewers from leaning over the couch.