By all means, use blankets. I had 3 brothers in WWII and my mother used their blankets as batting for years. Also, there may may be a military surplus store near you where you can sometimes get blankets for $5. Check them out. Should you find some wool blankets, be sure to preshrink them several times. They will be warm and cozy and heavier than regular batting. Should one not be large enough, get some of the tape that seals batting edges together and press the edges together until you can get it quilted. Hope this helps.