I'm in MN, too, so I know what you're talking about with cold winters. One concern that I have with your coop size - besides not having enough room - would be ventilation for the winter months. Your chickens will do just fine in the winter without a heat lamp, but they do need some airflow in their coop. Not much - not enough to cause a draft or be strong enough to ruffle their feathers - but venting high enough that the moist, stale air can leave the coop. My one coop is a 12'x8x8' shed type building with vented soffits. The other is 15'x8x8' with ventilation around the tops of the walls. Ideally, the ventilation is above the roosts, but both of my coops have open rafters and my chickens like to roost on them. The chickens will also need space to move around in the winter. Mine spend the better part of at least 3 months rarely leaving the coop. They almost always have the option to do so. The pop door is open to their attached run 24/7 except for the very coldest of days. (I usually shut it when it's double-digits below 0)
Some of the predators we've had to deal with in my part of the state (west central border) are raccoons, fox, coyotes, weasels (the small ones), minks, hawks, skunks, rats and potentially bald eagles. We also had oppossums around here for a while, but thankfully I think they've all frozen out or moved on. Oh - and various dogs - unfortunately, those were all our own dogs, but those are more easily controlled than a wild predator.
I am of the same opinion as Ridgerunner and Mrs. K - I'd hold off on getting a rooster for at least a year. They will change your flock dynamics, and if you want your kids to have part in raising and caring for your hens, I would suggest you don't get one at all. As Mrs. K says, without a rooster, they will be more dependent on you, making them more likely to come to you and let you or the kids handle them.
Some of the predators we've had to deal with in my part of the state (west central border) are raccoons, fox, coyotes, weasels (the small ones), minks, hawks, skunks, rats and potentially bald eagles. We also had oppossums around here for a while, but thankfully I think they've all frozen out or moved on. Oh - and various dogs - unfortunately, those were all our own dogs, but those are more easily controlled than a wild predator.
I am of the same opinion as Ridgerunner and Mrs. K - I'd hold off on getting a rooster for at least a year. They will change your flock dynamics, and if you want your kids to have part in raising and caring for your hens, I would suggest you don't get one at all. As Mrs. K says, without a rooster, they will be more dependent on you, making them more likely to come to you and let you or the kids handle them.