Welcome to PA, Archergirl. It nice to see another woman in our ranks. We have too few and welcome you among our ranks.
I can't be of help with the flax seeds but I'm sure others that know more about it will chime in soon.
You might try getting in touch with your local Ag Agent of the agriculture/horticulture dept of your state university. One of them should have info about growing flax(or not) in your area.
There are other options for making cordage from local weeds like milkweed, in your area.