How do I roughly cut linoleum to room width?
Instead of trying to work with the flooring in a cramped space, I use  a roll of craft paper and sticky tape to make a template of the room.  Start in the center of the room, lightly stick a strip to the ground, and cut it at the edges of the room.  You get a cleaner edge by going a little past the edge, then folding the cut edge back and sticking it down with the tape.  Keep sticking more strips to the template until you cover the entire room.

While you're doing that, lay the flooring out somewhere that you do have the space to work.  When it's ready, put the template on top of it, and cut around the edges.  Regular scissors work well for vinyl flooring, and I know I've installed real linoleum, but can't recall if scissors were OK or if I had to use something more heavy duty like tin snips.  Now that it's cut to size, you can easily carry it to where you need it and unroll it.