We tried cutting the carpet with lineman snips, but the narrow metal handles are hell on my hands. So we went to Harbor Freight looking for something easier. The electric shears were too expensive and too unwieldy. We looked at utility knives and a carpet cutter that resembled a giant paper cutter. Then I found the hardware scissors. We came home with a pair of Pittsburgh 11 1/2" Super Power Snips, angled for cutting against the floor. (They also have a straight version.) They have extremely thick blades with a double pivot and long handles sheathed in plastic. Advertised for cutting metal, they go through old carpet quite nicely, which is to say my small flimsy hands got a useful amount of work done before wearing out -- we got much of the carpet actually out of the house today. \o/ Basically these things are like branch loppers; we have similar designs in a shorter palmtop style and various longer two-handed ones. In fact our best long loppers have a compound ratchet that's a little more advanced than this.
Accomplishing anything with handywork makes me happy. I'm not very good at it, but I am proud of what I can manage. My partner Doug did most of the heavy lifting and pulling while I did the floor work and cutting. Yay us. We really like Harbor Freight because they usually have tools there that'll get the job done. Some of the things we've found there have quickly become go-to items, and I'm sure these snips will too. So if you need heavy-duty scissors, check them out.