Combines frozen ground

I doubt it. If that was the high for about 5 days you might get by with it. But you never know until you try, just don't get to brave, right away.

Try in the early morning, it is probably the only time it will hold machine on surface. If corn is tall enough to make good shade in the rows you can expect some problems only in end rows which are more exposed to the sunshine. less grain in tank (more unloading) machine will sink less.