Short form: best way to insulate workshop/summer kitchen attic ourselves in cold climate with existing floors?
Long story: We recently moved into a c1890's 1600sq 1-1/2 storey home near Montreal, Quebec (climate zone 6). There is an attached summer kitchen (18' x 20') at the back of the house that we use as a workshop. It has an attic that has 1" pine flooring, the workshop/summer kitchen below has ~1/4" beadboard ceiling. If there is any insullation in the summer kitchen walls I'd venture to guess it's about 100 years old and now rests in the bottom 5" of the walls. The attic floor/rafters were never insulated. We know how to tackle the walls but not so much the attic.
We want to continue using the workshop throughout the winter, wondering what the best approach to insulating it would be. Removing attic floor and insulating ceiling? Cut holes in floor to blow in insullation? Lay right over the old attic floors? Since the first floor will never be a finished living space we are approaching this task with lowered standards. Attached photos are of attic space above summer kitchen.