Snow, I'm so sorry for you and for him. He sounds a wonderful lad, but to be honest, it's not just the size of the house...his strong prey drive might well have been a problem to you in the future, as he's big he's probably pretty strong too, you wouldn't want him pulling you over. Candy is a small cocker but she's nearly had me off my feet when she's suddenly surged forward after a cat under a car! I think that could have been a worse problem than the size of your house, I've known someone kept two great danes in a not very big flat but he walked them for hours every day. Don't beat yourself up about it, the extra information about him that you can give Lisa should guarantee him the right home next time, and the dog you should have is waiting for you..somewhere! I've seen some crackers on GDS (Spanish based rescue), some pretty small.
We once got a female grey from Ireland that we thought would be a good match with Dylan...she went after four days, she attacked him twice and bit him quite badly on his back. With the best will in the world things don't always work out the way we hope they will. xx