Planting a grazing pasture
As you may already know, Coastal Bermuda is a hybrid bermuda grass that is propagated through sprigs (roots) or possibly tops. Even though this grass is not currently growing, Coastal sprigs can be dug and planted now. Tifton 85 is another hybrid bermuda grass variety and it should not be sprigged until April 1st at the earliest. Texas A&M AgriLife has several publications addressing the questions you pose.
I also encourage you to contact your local county extension agent. His name is Tuffy Loftin and he can be of great assistance. 903.536.2531