Report them to animal control, the sheriff or whoever the animal authority is in your area, there are things that can be done.
Does the dog have a proper shelter to get in from the cold and wind, enough straw or blankets. Melted water available to drink while they are out. Letting the dog eat snow is not okay. If they want to that’s fine they shouldn’t have to if they have enough to drink.
Food does not need be available outside, it attracts rats and other animals, the dog should be fed at least once a day.
If there is no dog shelter (tents or overhangs or under the boat or truck doesn’t count. Being able to walk into the garage doesn’t count as the dogs body heat cannot warm up the garage so he can get warmed by his body heat. Turn them in or be just as guilty of letting him suffer. If you witness cruelty then your part of the problem if you choose to do nothing. It can be anonymous and you wouldn’t have to talk to the neighbor again.
Dogs can be left outside unfortunately but they need adequate shelter to be comfortable both summer and winter. Dogs that constantly bark, whine or cry are a nuisance and if nothing else the health department may be able to step in as its disturbing the neighbors even during the day. Most cities let dogs bark and carry on…. ten minutes and after that the dogs must be quiet for a while. If their yards full of dog poops that’s also a health issue and they need clean it up even in winter.