If I had to do business casual, I would dress no differently than I do on weekends and holidays when I have to look semi nice. Basically, I only have three speeds.
1) Classic tailored jacket & tie
2) ratty chinos/shorts + cal or wharf to whart or cactus league t-shirt
3) tailored odd trousers + BD (OCBD for cold weather, linen for warm).
So, I would do #3, with loafers or bucks.
yeah, that's what I figured.
what about thicker shirt for cold weather? like wool or cotton chamois?