I think you nailed it.

Having had a similar situation, and if the will said cottage to be divided in 3, my solution would be to give each a third of the cottage, that comes with a third of maintenance costs.

Then the non-cottage-loving sibling has to decide on a price to sell it to the other two to get out of the responsibility, the agreed price will include the perceived value and maintenance costs each sibling thinks is fair.

More complicated, but obviously its already complicated, and probably more fair.