the question is....can they be left on through winter if the insert is placed in?
anyone out there absolutely hate screened bottom boards?
I wouldn't use anything else. Next winter I'll place insert boards
under the SBB, place a standard entrance reducer in (with the
smallest opening showing) and using the little half moon cutout
of the inner cover for a top vent.
Our weather is about 10 degrees different during the winter months.
The snowfall you get is mostly wet, while I receive rainfall due to
the higher temps.
If snowfall blocks your lower entrances, the top vent still allows
for cleansing flights. I think this would work for VA also.
BTW, my brother lives outside Lynchburg on 3 acres, it's beautiful there :)