I haven't had any issues with a stiff extension cord. This is what I'm using, except I paid quite a bit less for it a few years ago when I bought it. They also have the same cord with a greenish color and a red stripe but the rest of the packaging match and they are both 100 foot 12 gauge cord with a standard 120v 15 amp plug. It doesn't say its a cold weather cord but it does the job and I don't bring it inside or anything so its cold all winter. I originally bought it for the electric mower but when I bought the electric snowblower its been fitting the bill just fine.
12-3, 100', 1 Outlet, Stripes™ Orange/Blue Extension Cord at Menards