the key is whether they can move around, go to the their dog house or get under the porch or other cover....
out dogs were never chained up...
on extremely cold nights, we let our dog into the garage...
our dog lived til almost age 18...and we live in the cold north...
That's my experience, too. Every dog I have ever had has exceeded its breed's typical life expectancy and usually by a lot. They were almost always outside but always had adequate food, water, and shelter. When temperatures were at an extreme, extra measures were taken including bringing them indoors. Dogs (and cats) aren't quite as delicate as some people think.