ooops! even after all that talking, i still didn't answer the question all the way.
the warm & natural will definitely shrink - - - the fleece hardly at all. if you want to pre-shrink the w & n put it into a large cotton 'pillowcase', safety pin it closed, wash on hot very very very gently. after that dry it, opened out flat on a sheet on carpeting. you want to keep it flat, flat, flat. don't try to drape it over something to dry. you can dry something smaller on a bigger bed, like a single quilt on a king bed. but it must be flat. block it very gently. it stretches like crazy. i put another sheet over it and (gasp!) walk on it very carefully, no shoes, to squeeze out as much water as possible and flatten it out so 'pooches' don't dry into it. it can take several days. be prepared. if you can wait, do it in the winter when the heat is on. otherwise use lots of fans. i choose not to prewash for exactly those reasons. i wait until the quilt is done and then wash it gently. the shrinkage gives it a real 'quilt' quality. all of the batting companies will give you great instructions for the care of their own products. on their websites, use their comment box or contact us box. they all answer right away. some will even send samples if asked. then you can test washing.