Dalian gets some snow, but its winters are typically largely dry, meaning its just cold, but clear, so should still be possible to work as normal even during winter. Will just be a bit uncomfortably for the workers.
Also, as big as the carrier and dry dock is, its not hard or that expensive to cover it all up with temporary tarp covering if that is deemed necessary. Would make it a lot less uncomfortable for the workers, but they won't be able to use the big crane if they do that. But that could be worked around.
In any case, I do not expect the winter to disrupt construction much, although obviously, work will probably stop for the usual amount of time over Chinese New Year.