Based on that pic, I'm betting a typical tandem would fit. As Ritterview noted, there's plenty of room above. There's also more than a foot below. So with the back wheel on the ground, and the hook on the front catching the back of the front wheel, I think it likely would squeeze in.
Another option would be to remove the front wheel, and hang the bike by the back wheel.
Bringing a luggage strap with you might not be a bad idea.
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You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.