Sounds like a decent reflector setup, But 1 thing, aluminum foil is more expensive than going to Wal-Mart and in the camping section, they have these awesome things called "Emergency Camping Blankets" $4 ea. And each blanket is 52"w X 84"h. It covers a lot more area for a better price. Not to mention, it wont retain heat the way foil does. Try it and lemme know what you think.

Good Luck!

Wenzel Waterproof Emergency Camping Blanket - Walmart.com