If you can sit through the unexpected cold burst, you can "get by" with 50/50 antifreeze as it'll turn to slush that doesn't expand and doesn't blow out your freeze plugs etc.
In other words it doesn't freeze like plain water.
Naturally though we like cars that run, and a water pump churning through slush sounds like trouble brewing.
It's easy enough to mix 55%... grab an empty gallon milk jug, fill it halfway(ish) with water, then tap your gallon of AF and top off the milk jug. Fill the (now-half-empty) AF jug with water but leave a couple inches at the top. When you fill your car, flip flop between your two jugs until you get a gallon in there, then dump your milk jug back into the AF jug, finish filling the car, and mark the leftovers so you don't assume they're 100%.
In other words it doesn't freeze like plain water.
Naturally though we like cars that run, and a water pump churning through slush sounds like trouble brewing.
It's easy enough to mix 55%... grab an empty gallon milk jug, fill it halfway(ish) with water, then tap your gallon of AF and top off the milk jug. Fill the (now-half-empty) AF jug with water but leave a couple inches at the top. When you fill your car, flip flop between your two jugs until you get a gallon in there, then dump your milk jug back into the AF jug, finish filling the car, and mark the leftovers so you don't assume they're 100%.