Oh, I would add a gallon at a time of the 6-month old gas to your daily driving family mobil, as long as it has a near full tank. I really don't think one gallon of "old" gas to 18-22 gallons of freash gas will hurt things much.
Hate to throw away $4.00 per gallon fuel.
Home Depot has nice red 5-gallon plastic gas cans for about $8.00.