I make my own fleece housecoat for my Yorkie and when he needs to go outside, I put a Hurtta wind and waterproof jacket on him. My dog is 12 so he feels cold a lot these days.
With fleece, you can buy the thickness you want and you can easily handsew it if you don't have a sewing machine and you don't have to finish the ends as it won't fray. I've a hard time buying for him as he is very long and most sweaters that I buy is too short for him and if I buy the correct length the chest is too big.
Hurtta has some nice jackets with no velcro so they last a long time and it is so easy to put on it takes 5 seconds.
I make his booties as well double layer thick fleece and use drawstrings. I hate the velcro ones because they don't stay on. They are only good for the backyard as it'll get wet if it's on too long but it works for us. Fast to put on and fast to take off and the best thing is they don't fall off. I don't usually use booties for him but in -30 winter, it really helps his small feet.
Here's a pic of him in his housecoat. |