The .847 isn't super stable with IBT. So I did a run just now with .88 or so.
Here is a test I did a few weeks ago when it was really cold here in California.
The High temps in this picture are when i was running Prime95. 28c was the highest on that one.
And because you mentioned it, here is the 1.6v test. I didnt take a SS of the temps but this was on my old WCing setup so I would imagine about 70c.
When you say pretty cold, how cold was the ambient temperature?