I don't know anything about cold winters so can't comment on that, however more than a few times something to the effect of whites being weaker or harder to raise/hatch etc come up, so I'm guessing it may be in this group of "whites are weak" idea. In my experience there is zero difference between whites and blues except for color.
I kind of wonder sometimes if these claims come via there possibly being inbred whites.. as there also seems to be this idea floating around out there that to get "true whites" one must breed only whites to whites for "generations".. which may lead to some lines getting a bit inbred.. so maybe, inbreeding weakness? I've actually had more than few persons 'reject' my white chicks after finding out they were out of pied/splits or white x pied/split breeding.. in their minds they were not "pure white".. despite being solid white birds themselves..
None of my whites were out of white x white breeding, always deliberately crossed with whole slew of different colors from different sources over many years including silver pied, purple silver pied, BS silver pied, white eyed split white, currently raising blue split chicks from white eyed split for white bred with pure blue to add yet more new blood to whites, and so on(although after a massive flock reduction, I am going to have a pen of all whites this season..). Chicks hatch and grow same as any blue- very well n' easy.