Ooh, broccoli that can live through multiple winters! That's exactly what I'm trying to grow. I'm in zone 7b. I see you're in zone 8, which is close. Your seeds might work well for me. How heat tolerant were they when the summer months came along? Do they have any drought tolerance that you know of?
I live in Utah, in the middle of a desert, so I'm careful with
water. I highly favor drought tolerance in my warm weather crops, and I highly favor cold tolerance in my cool weather crops, because I'd like to be able to grow them through the winter, taking advantage of the only season where I have abundant water (a.k.a. snow). Squashes do well for me. What kinds of squashes do you grow?
I store my seeds in the refrigerator, so I've never had to be overly concerned with how long they're viable. Just by keeping them there, it doubles their storage life, or more than doubles it. I planted ten-year-old squash seeds this year that sprouted just as happily as the new ones.