There is a high demand for the plus size coats in the market, when you compare it with the plus size women. So here you need to search for the plus size coats. At the end people buys it online. The retailers mainly focuses on the slim fit dresses or skinny tight, some mainly focuses on the large sizes.
So there are retail shops in you country selling large size coats. But if you look into the number of stores, they are few in numbers. So it is not possible for people to travel along the far away stores to buy a perfect plus size coat.
The last thing that is left is the Internet. Here you get to choose varieties of plus size coats, so you can buy the best one that fits you. Also, there is a disadvantage in it, as you are unable to try the dresses, which you can if you go to the retail shops.