I haven't staked out exactly where, but Ideally, it would be some place just south of the tundra of Alaska or Canada, on a small hill / plateau. It would also be within walking distance of the sea.
The property would have a dual layer 16 foot tall reenforced barbed wire fence built around the perimeter (would for around 25 acres, or just over about 1000x1000 feet) There would be gates with gatehouses along 2 sides. One of them along the side facing the sea, and the other along any one of the other 3 sides. I would have the forest clear cut clear cut the forest for 200 feet between the fence, and it's outer perimeter (to make spotting zombies as they approach the fence easier)
Within this 25 acre zombie free zone, There would be a large vegetable garden, about 3-4 acres worth (it's a short growing season, and the soil isn't great, but the extremely long arctic days are supposed to produce enourmous cabbages and zucchini.) There would be an Apple orchard with about 100 trees. Inside those walls, I would build my inner wall about 150 feet by 300 feet, with towers at the corners, and along the center of the 300 foot wall sections. The inner wall would be 50 feet high and made of steel reinforced concrete, and 6 feet thick. Within this inner area, I would have my keep, it would be 150 feet by 30 feet in size. The keep would contain a 5 story stone building. The topmost floor would be used for housing. The first 4 floors would contain storage. Within this storage would be vast stockpiles of raw materials, food stores, fuel stores, tools, backup tools, backups for backup tools, weapons, backup weapons, backups for backup weapons, hundreds of thousands of rounds of ammo, and just about everything you'd find on a farm, in a shed, in a garage, or in a workshop....
Above the roof of the keep would be the greenhouse. It would be a steel structure with 3 seperate layers of glass windows with an inch between the glass. This would provide a very high R value of insulation, which would help it to stay warm. The rooftop greenhouse would be used to grow mostly cereal crops, as they are otherwise next to impossible to grow that far north, and they can provide very high "calories per acre" of food density ... enough such that if the fruit and vegetables all fail, and expeditions to the sea to fish or to try to hunt fail, there would still be something to eat, hopefully enough to sustain life....
For "power", there would be several solar arrays, several very durable windmills, and a coal fired boiler. There would be several seperate coal sheds on the property, 2 smallish shedswithin the inner wall, and several outside it ....
Split up and kept at a distance such that if one were to ignite/explode, it would nod destroy the keep, the greenhouse, the walls, and they would not interfere with each other. The coal would be conserved, and used sparingly, wood would be the fuel of choice due to the forest....
I would limit the population of my compound to about 25 people initially, any more than that, and the risk of starvation would be too high, any less than that, and there would be too much risk of not enough people to keep the place secure and maintained....