What sort of "all season" tires do you have experience with? Keep in mind these are performance all season, not touring all seasons. They are automatically going to be much worse in the snow than a standard touring tire. Someone already mentioned it but most OEM tires are quite bad in the winter - especially if its a performance all season. Go to tire rack and look at the ratings for the continental tires that come on the 19" wheels - they have horrible reviews. Tesla tilts all their cars toward max range, so you're going to have tires that are low rolling resistance and generally have bad rubber compound for winter. These aren't 'normal cars' where you commonly have pretty good tires that come on an SUV.
It is unfortunate that tesla doesn't do more education but I think they don't want to scare people away; so you end up just having to learn it yourself and make a judgement call for your own safety.
At least you don't own a performance car and have no understanding of what a summer tire is, and you absolutely should not be driving it in winter.....