I'm farming in the Mistlands using a bald farm: no fence, no support buildings, several defensive portals on high places around the farm, a workbench and some chests hidden under Ydgdrasil shoots along with the home portal.

I am there only when farming. The idea is to avoid events other than "You are being hunted."

It's working well, I have lost parts of two crops when I couldn't stop enemies from blundering over the farm, that's all, but I don't think it's something that will or should be possible in the finished game. Irl, if you had crops without a fence, something would eat them. (Wtf do all the misthares eat?)

If you like to play the game as it should be, you might want to build a fence even if you don't need one now. If you don't create any buildings close by, it won't look like a base. My barley farm in the Plains has a stockade around it, but no buildings. Farming there has been peaceful.