I need this

Me but maybe a little bit longer on the foot side

Polygamists?

My wife would still only leave me a foot of space on the edge.

Looks like it's The Ace Family Size, which are 80"x144" (slightly over 6 and a half feet by 12 feet) which is fantastic, but man are they and their bedding expensive.

When I was young I imagined an entire room that's a bed except for the door area

This is made for families who co-sleep, which is sharing a bed with parents/children/pets etcetera. Or just you and your giant ass.