If you think about it, a twin boxspring will go about anywhere. A full boxspring will also go about anywhere except the tightest space. Of course, we sell split full or double (same size different name) size boxsprings but they are rarer. Most mattress stores can only special order these. A king size comes with split boxsprings because it would be difficult to get it into most bedrooms, plus it would be very heavy. A queen is also large but it most be special ordered split. I would say that a queen size box spring will not fit into 3 per cent of the bedrooms in the US. Maybe 2 per cent. Whatever the true figure is, that is the way it is.
Some people will just sit a queen mattress on the floor if their boxspring will not make it into the room. This is college student style and many people will not tolerate it. The downside of keeping your mattress on the floor is every critter, spider and bug will enjoy the bed with you. The feet of a bed frame help keep bugs out of your bed. A mattress on the floor will also experience more cold drafts and lots more dust. Also, a mattress should breathe and having it lay on the floor stops the transfer of moisture and fresh air.
I have seen several attempts at cutting a queen boxspring into two to get it upstairs and then re-assemble it. I have even seen a box spring re-assembled with duct tape, for real. These brutal attempts do not work very well with bedframes or proper support.
The proper way to manage the problem is to purchase a split box spring set. The same type of set can be purchased as a split foundation set. This foundation set will look like a twin box spring set but will have a wood and card board top and now flex springs. It is a cheap alternative and really only good for guest beds, in my humble opinion.
Split box spring sets can be difficult to come by. We sell an excellent set on our website. Anoher alternative is the smart base. The queen smart base is a high frame that comes in a relatively small box so it can fit through any door. It is tall enough to not need a boxspring so the problem is solved. The down side of the smart base is strength. If your bed sees lots of activity, it may not hold up over the long term.