I store my freshly-processed chickens in plastic grocery sacks, stick it in head(less) first in a bottom corner and twist it tight over the ends of the drumsticks. Then I twist the handles into cords and wrap them around those bones to tie. And I agree, let him rest for a few days, then roast him slowly with low heat. You can put some veggies in the pan with him, some potatoes, onions, carrots, celery, etc. You can use a covered pan or a roasting bag. He should be fine like that.
You did good with the dispatching, and no, you don't "need" a cone, it's really just to keep the bird from flapping & thrashing. You can hang him by the feet & let him flap, or you can wrap duct tape around him a few times. The plucking sounded like it went well, it's the easiest part for me. I always leave those lil' feathers around the hocks to pluck when I have him on the cleaning table, or when I'm giving him a final rinse before bagging.
Be sure to tell the Missus that we're all proud of her too, for getting that icky job done by herself. Enjoy your tasty meal, let us know how he finishes!