Yes they are edible. Depending on the breed and age, you may have to rethink what cooking chicken is all about. It won't likely to be a 6 week old Cornish/Rock cross. What makes up 100% of fast food chicken and 98% of grocery store chicken. You can't cook it quickly.
After processing, it needs to rest for several days either before or after freezing so rigor mortis will dissipate. Secondly, you'll need to cook it on low heat and very slow if you want to do the entire bird. That means about 225F for 5 hours or till the leg meat starts to fall off the bone.
A better method is to part the bird out since the breast cooks much faster and treat each part differently. A crock pot is always a good option, soup or casserole.
The good thing is that a mature bird is much more flavorful because they have had time to develop real chicken flavor, not like the flavorless grocery store bird.