From my view down the valley I see only cloud and mist.
From recollection the main stand casts a large shadow over the ground at this time of year so a large patch on that wing stays frozen. We have had games called off due to this before.
The sun sets at just after 4pm so the ground would start to re-freeze pretty quickly unless we had a really warm day.
I'm not sure how effective covers are, especially when laid on top of an already frozen pitch.
My lawn is solid and there is an inch of ice on the rain butt, but I am half way "up the hill" and its quite often colder up here than the valley bottom.