They managed it fine without problems last winter so they ought to be fine THIS winter.
Do know that for the breed, your birds are getting old. Japanese Coturnix Quail have a life expectancy of two years, but do most of their laying the first year. That said, you can expect that their egg production will drop off from both their 'senior citizen' status but also the reduced hours of light provided by mother nature. Have you considered hatching out some of their eggs for the coming season? If started today, you could have a fresh replacement flock grown to adulthood by mid-January.
A clutch of a dozen or so eggs incubated should provide you with a fresh cock and four new hens. I get that count knowing that some eggs won't be fertile, some will quit mid-hatch, some will die within the first two days after hatch, and some will only survive a week after hatch. Once they're about two weeks old, mother nature should quit culling your hatch, and only the strongest birds will remain. Your next hurdle will be the transition from brooder to the great outdoors. Some birds may be lost once they come out of the brooder and onto the soil due to coccidia, but you can greatly increase their odds of making this transition without illness if you proactively treat their water with amprolium for the duration specified on the packaging as soon as their 'boots hit the ground'. Over time, your birds will develop resistance to this microscopic parasite, but as with most disease, it hits the old and the very young the hardest.
Should you have more birds than you need from your hatch, you can either process them for your freezer or gift the live birds to a friend or neighbor to get them hooked!