We used do that trip a lot! Depending on your budget there are quite a few places in and around Nantwich/Sandbach that could make a good overnight stay. Money no object options with pools are Crewe Hall or Rookery Hall, more down to earth The Cheshire Cat in Nantwich or maybe the Bear's Paw in Warmingham? Several Premier Inns and Travelodges around there too.
All about 10 mins from junction 16/17 and Nantwich has a nice riverside walk with park and swings etc, pretty town centre and big Sainsburys on the ringroad!