I use 6" long lag screws with washers and a battery powered screw driver I bought at Walmart, The one that uses AA batteries so I can carry extras. I load the Doghouse, Buddy heater and my fishing equipment into a Mini Otter sled and I can go just about anyplace I want. I'll drive to a spot if I can, but most of the time I can't get out onto the ice with my car. (no 4x4)
The Doghouse works great for this, and for other things as well. I have 2 of them, an ealier standard model and a new TSC. When camping I use the standard model as an outhouse. I use my hand ice fishing auger with an extra set of dull blades, auger a hole a couple feet deep, I have a camp stool rigged with a toilet seat and set that over the hole, throw in a little dirt each time you finish and it keeps the smell down

and I have a nice comfortable private privy.
I thought I should add that most of my camping is done primitive, and usually on private land. Make sure the landowner is OK with this, or if on public land that the regs allow for it.
huntin1