Fellow Idahoan checking in.
Skip the insulation, unless you like to provide free housing to mice. Every outbuilding I've ever seen with insulation turns into a mouse hotel with the quickness.
Skip the heat unless you're brooding chicks. Chickens have one of the best forms on insulation nature supplies in their feathers. They will acclimate to the colder temperatures and fill out with feathers. The problem with heating the coop is two fold.
1. in order to maintain good air quality in the coop you need to have tons of ventilation, ventilation and heat don't go together very well. If you shut the ventilation down to conserve the heat you're going to have a very swampy coop in a very short period of time.
2. If the chickens don't acclimate to the colder temperatures they won't do well if you have a power outage, and they will be less inclined to go outside.