Hi Akwood
Well here is my 2 cents worth on this subject
--not much drying will take place when the timber are in a frozen state
--Historically the timbers were cut in the winter time when most of the sap had decended into the roots of the trees, but having said that remember that depending on the type of tree some do not have sap, and retain their (evergreen) characteristics through the winter.
--Hardwoods, are better cut in the winter, Ie: less moisture to contend with, and the lumber piled and covered for 1 year for every inch of thickness--rule of thumb!
-- round timber should be cut in the cold part of the season, sawn or hewn before spring, and then piled and cured for 1 or 2 seasons --with a cover of boarding (to keep the sun off), and piled one on top of the other using the weight to prevent twisting during the drying process.
NH