It’s not about the size of the room, but the utility of the space...
Trust me, I have seen enormous rooms that just don’t work.
Don’t allow the fact that a prospective home doesn’t have a main floor laundry to deter you, particularly if everything else about the property fits your criteria. Envision your space, friends, and scope out a closet near a current restroom or plumbing stack on the main floor to convert! Problem solved with a healthy return on investment.