the max i reached was -250cold resist from cold mastery(i think you can got so much you will,you need only skills

),but if you take in all items facets-cold resist:
cold mastery at lvl :41-43 (-220%cold resist ---- -230%cold resist)
-weapon

oom (2 skills to all) can have -60 cold resist or Death's Fathom (3 skills) can have +30%cold dmg socked with facet +5%cold dmg -5%cold resist
-helm:harle (2 skills) or Nightwing's Veil (2 skills and can have +15%cold dmg) socked with cold facet +5%cold dmg and -5%resist
-armor

rmus can have +20%cold dmg socked with facet +5%cold dmg -5%cold resist
-rings:2xsoj (2 skills)
-belt:spiderweb (1 skill)
-amu:amu with 3 cold skills (3 skills :P)
-shield:lidless (1 skill) socked with facet +5%cold dmg -5%cold resist or 4socked shield with 4 fackets +20%cold dmg -20%cold resist
-charms:10 cold skiller (10 skills :P)
its not a guid because you need for pvp something for antifroozen , i write this only that you can see what its possible

-charm:anni (1 skill)
with adding all you can get
-cold resist:245-320
+cold dmg:55-100
i hope i could help you with this,because its half a guide :P and i hope too that i don´t do mistakes