Sorry, I didn't mean to start a debate, but because crating is not an option here, we simply have to teach all and any dogs to stay home alone. And they do learn, so if you want to train your dogs to be home alone also without crates, I'm sure they will learn. Just start with the short times and maybe leave something for them to do (like eating a small bone or activation toy) for few first minutes alone. Though be prepared that they do not actually do much home alone. My dogs for example spend probably 90 % of their time alone sleeping.
If you want to walk them during winter, they will get used to it (but do use jackets.) Boston terrier is very popular breed also here and they do make long walks also in snow and cold.
Do you have Ikea anywhere near you? They sell good and affordable child/animal gates that you could use to make your dogs stay in one room or to stay away from certain rooms (cats can easily jump/climb over)
