Will this work for a standie?

I have a pop up tent trailer, that is mostly dismantled, and I therefore have a frame etc, with a dimension of 72 inches by 141 inches. This seems too big for a standard teardrop, but I wondered about doing a standie with the same type of dimensions as a camplite 11. I started playing around with the graph paper (old school, and have no idea how to use sketchup
) I hope to make the outer dimensions 80 by 141 inches, and the height 78 inches. Here are the scans of my doodles. Please let me know what you think.

