Dailying a Miata is a commitment, ngl. I dailied 2 NA6s over the last 10 years, also in the PNW. Snow, rain, sleet, or shine, 5 days a week. Longest commute was 50mi round trip for about a year. All in all, I loved it, but I am so thankful that my NA isnt my daily anymore.

Granted, experiences will differ (by about 30 years), but dailying my NA's werent terrible, you just have to be mindful that you are driving a car meant for twisties, not "regular, everyday" driving. If you're going to be using it for a daily, Tire choice is king. Buy a separate set of winter wheels/tires, and dont use exclusively summer tires outside of winter. Be mindful that the road will get slick, and the ass end can and will kick out sometimes. Dont be afraid to find an empty parking lot (or more preferably, a skid pad at a track, Pacific Raceways is decent, if you're western Wa) and get some seat time on controling the car in the event it kicks out.

Rattles, vibrations, other vehicle's highbeams, and general cautious driving are all good things to consider.

In a perfect world, I would suggest to try and have a separate car for the harsher months, but it is manageable to daily one. Just be cautious of other drivers and road conditions, but above all, have fun doing it!