Awww!
Sounds like a crazy mix, though! I can’t imagine my dog in a bigger size - he’s rather like Tigger, and more of him would be a little scary! ;-)
Yours is just tooooo cute and I am sure that you'd love him whatever size he came in. Mine was a perfect Border Collie in size until he hit eight months old -- until then, everyone thought he was a purebred. Then the legs started to grow and the body started getting longer and he morphed. When he got taller than our other dog, we really knew his growth was on a roll, but we weren't sure when it was going to stop! Thank God, he didn't hit Great Dane size! But when he was finally grown, that was the only way we discovered his Dane half. Got him at the shelter and they said "mix" but not what kind, and the vet finally nailed it after Harley was grown.
He really is a very good boy.