So although you may not be real proud of this dog house, you may have inadvertently answered a question that's been hanging about. People have asked about using an alternative material to canvas and t-shirt material has been proposed but as far as I know, nobody experimented with it. Now you have and we know the results.
Next it will be time for you to build a foamie of your very own. Make sure you leave bed space for the dog. It turns out to be a bigger space than you think. For my 45 lb. lab/beagle/pit bull mix, it's a space about 2 ft x 2 ft x 2 ft. My wife's 6 lb poodle just sleeps on the bed.
Thanks for adding to our collective body of knowledge