It appears my limits are reasonable. Funny, I've had the impression I was crazy for biking in this weather. For my commute, which is short, the limit is what the world throws at me, which yesterday was 5F, and that was painful even for the short distance. But if I lived in a different climate where we routinely got that cold I'd have better gear. I have good clothes and equipment for this climate (the midwest).

If I lived in a milder climate, there'd be no point in having all the gear I have, so I wouldn't have it, and my cut off would be much higher.

That's my commuting limits. Wild horses couldn't drag me out on a recreational ride below ~50F. And yesterday was too cold even for wild horses. (Ok, all the horses around here are in pastures. Not exactly wild.)