You can and should have pretty good results with the exception being if any of this years plants were hybridized. Most hybrids (where two or more plants are used to produce a desired characteristic) are sterile...
I'm sure they will germinate. I do this most years and plant half of the seeds in a sheltered spot at the end of October. If you store seeds keep them in a paperbag. Good luck!
I live in the north of England and it works without problems. An idea might be to plant them in pots and store in a sheltered place before planting them in their final positions in spring.