Too many variables to account for over different waterbodies. Depth, current, wind, snow cover, etc. They all cause too many variables to fit into a single spreadsheet. While 3 to 4 night below -10 C may freeze a small pond solid from scratch, snow cover on the pond will lessen the likelihood of it being safe.
What I've found more effective, is logging ice thickness in my fishing log for every outing. That way, I can reference previous seasons of ice on certain smaller waterways in a given region, versus bigger nearby lakes, etc. So by example, having 7 inches at one lake, means that I'll likely find 4 inches on another, as long as they are close enough to each other.
Still, not a perfect science, but about as close as I'll get trying to gauge ice remotely by following regional forecasts remotely without being on site. But after nearly a decade of logging ice thickness, I have a good idea of what to expect when I arrive.
