You should be able to see the flax/barley from outside the village. I would just just sneek up close enough to confirm if there's any flax there and move on if it's not.

In my last playthrough I was looking for the totems, and I just sailed around the coast of plains regions and tried to spot the totem from the ship. It's probably easier to spot a totem than to tell the difference between the crops, but it could work if the crops are close to the shore.