I don't have any empirical data on this, but i do recall reading an article a long time ago on the effects of various types of runway contaminants on the landing performance. It was catered toward bizjet airplanes, but the numbers should be pretty close to the mark for commercial airplane types too. With wet ice - or anything with braking action poor (or worse, nil), landing distance required (LDR) increases in the order of 3 times (if memory serves correctly). That pretty much precludes most runways in normal line operations. Even if that number is overly conservative, i don't have any qualms about diverting off somewhere where it's nicer... Don't need to be a hero here, esp for ppl who don't operate in this kind of condition day in & day out. Nobody's gonna give you a pat on the shoulder for sliding off the r/w!
My last 2 airlines both had company policies prohibiting landing in POOR braking action anyway.