HMMMM how do I say dejavue (I think) Same problem I lacked a 4 footer that got damaged in delivery. I ended up getting a cheap section at the hardware store and put that at the highest point. I used a kerosene heater in the sugarhouse and then lit a handful of twigs and just kept feeding that for a bit to get the arch toasty then I threw in a heat lamp and left it for a few days. Oh yea it was January when I did it too. You are gonna be fine the way your plan is.
I did get the new ss stack section from Patrick by the way.