This is where the spirit of experimentation kicks in; sounds like you have a ready supply.

If you just let the seeds on/in the ground they will get a natural stratification. And if the seeds are "good seeds" they will germinate next spring.
Besides.... I have sown various kinds of Picea seeds the last couple of years (in april), without stratification and they came up well. Only minor disadventage is that some seeds take about three-four weeks before they germinate, others five, six or more weeks. Even in july I had a few that germinated.....
One advantage of stratification is that they germinate (almost) all around the same time, and perhaps a few day's or one week earlier (in the case of Picea).