I live just 30 minutes west of Crossville in Cookeville, TN and highly recommend the entire area. Winters are short and we have 4 distinct seasons. After living here 16 years there has never been a winter bad enough that I couldn't get around in my 2wd pick-up. Crossville did have a bad freak ice storm last winter. Many retirees of all types are relocating to the area.
Chattanooga has milder winters but the tradeoff is hotter, longer, and more humid summers. Both areas have good roads but Chattanooga wins for more interstate choices. Northeast to Knoxville, Northwest to Nashville, Southeast to Atlanta, or southwest to Birmingham. The Crossville/Cookeville area has I-40 for east/west and 111 or 127 for south. North from either into Kentucky and beyond is just curves and hills as soon as you cross into Ky.
So many retirees from Florida have moved here that they have their own name, Half-backs, as in have moved halfway back home.