i (along with most fixie riders i know in nyc) ride MKS sylvan track pedals year-round on the street and maintenance is a non-issue.

they're cheap pedals and don't spin as smoothly as high-end stuff, but i rarely feel like they need work. i might rebuild them once a year or something when i'm overhauling everything, but you're putting too much thought into this.

they're not going to seize up after one ride in the rain or anything.