I have been giving both packaged and heirloom. The last two packages also had more than 20 packs too. I am technically giving more than I am advertising....whatever fills the package.
I can't believe to pretend I know the weather in your area. I can only say that that this variety contains seeds that are good for all year round in my own. Broccoli for example is not a summer crop here. But, corn is. Radishes and lettuce would be available in a week anywhere in my area. Cabbage is great for winter anywhere.
I am confused by your question: "sealed packets of seeds"???? What do you mean? Unopened and new packaged seeds? Yes. heirloom seeds properly stored and sealed? yes. This covers veggies above plus more.