How to winterize a dog house for heat.

Is it a wooden house? You can use foam board on the inside. Just nail or use adhesive to attach foam board to the floor, walls, and ceiling. Also putting a DIY pet mat on the floor of the dog house. This is easily made with canvas material stuffed with straw or sawdust. Hang an old piece of material over the entrance to block the wind. Try to position doghouse close to fence, shrubs, house, etc to help block the wind. There are electrical and nonelectric pads to use for pets. Not sure of the price, but might be worth checking.

How about just letting the poor dog in the house

Be careful of any type of insulation... dogs like to tear the stuff out and eat it... Carpet stapled onto the wall can help insulate it... rubber padding on the floors too... If you have snow... moving the dog into the barn or garage would be better and a dog door installed so they can go in and out. A wood pallet with a plywood top and a heated rubber mat would keep them warm and off the cold concrete or damp earth (especially for an older dog). We had one Vet tell us that for a dog with arthritis, it was better for them to not go in and out from a warm house at night to a cold yard to stay all day. better for them to be cooler and out of the wind and snow, than too warm and then too cold.

If your family doesn't have allergies, you can put hay in dog house. It allows air to circulate but helps keep dog warm. Probably more healthy than trying to regulate an electric device, some dogs skin are sensitive to burn or injury.

Keep the poor dog inside. To " guard" the house there are alarm systems for this.

I would look into under the floor heating. It works wonders in a bathroom so why not here also?

Just seems logical since heat rises. Nothing better then setting your feet on a warm surface. Should apply to pups too.

Take a page from chicken farmers. Hand a heat lamp in the dog house. Careful using extention cords.