If you're out in the woods then no one is likely to bother you about building the cabin in the woods yourself without a permit.
Still eventually the tax assessor may eventually come around and notice the cabin but even then they might just assess the cabin for the taxes and then leave it at that.
Still someone might come and check on the building of the cabin but if it's just a cabin for camping in at certain times of the year then no one is likely to bother you about the cabin.
I built a cabin in the woods 10 years ago and although it's now listed on the taxes I've never had a problem with the legality of building the cabin in the woods and no one has said anything about it.