You'll be fine. Grass barely notices a frost and is completely frost-hardy in seed, sprout, and mature form. Treated properly, it can be kept green in temperatures down to 15°F (-9 C) or even colder; I manage this every year, although it won't grow at temperatures much under 38° F.

However, keeping it green that cold does require some special care that most people aren't interested in supplying. I'm a hobbyist and am disappointed by dormant grass in February.

Also, ignore forecasts that far out, they're incredibly unreliable. If it still says that on October sixth, they might have something. :-)

Thanks, morpheus. The person who sowed it insists it will winter kill, something that seemed ridiculous to me, but I wasn't sure how well it could handle frost/freeze when it was still quite young.

Winter kill in WV is...incredibly unlikely. North Dakota, maybe. :-) And even there, lawns survive winter year in, year out, without noticeable problems. Grasses are incredibly hardy things--bluegrass is hardy to Zone 2.