It's easy to bid 6NT which has no chance as the cards lie.

This auction gets you to 6♠ when North 'breaks the transfer' to show four Spades and a doubleton. South doesnt need to use Blackwood because at most six Points are missing

To make 6♠ you need to Draw Trumps, Cash the two Top Diamonds, Cash ♥ A K, and then play ♣ A K and another Club hoping that whichever hand that has the ♣ Q is left with no Hearts and has to give you a ruff and discard. It's a case of a slim chance being better than no chance!