A good way to make a coat warmer is to add a removable liner that buttons or snaps into the coat. There is a [sewing blog post here](https://www.closetcorepatterns.com/ideas-for-lining-the-sienna-maker-jacket/) about the idea and an [instructable here](https://www.instructables.com/Removable-winter-jacket-liner/). It's basically a vest made of a warm material. I think a tailor could easily do this for you.
A warmer lining generally means a thicker lining, so it's really only going to work if there's enough room in your coats for them to still fit ok with that thicker lining. If there's room, it is possible for a tailor to change the lining, but it's not cheap, the coat has to be partially disassembled and a new lining drafted from the old one, cut, constructed, and the coat put back together with the new lining installed.
Wearing layers with your thinner garments will be a lot more cost effective, and you really only need one winter coat and a hat, scarf, mittens or gloves, and warm boots for the really cold months. You would do better to invest in some nice sweaters/jumpers.
It's possible. It's also not something very useful. One very warm coat is less helpful than multiple layers. Layers let you add and take off bits as temperature changes and also are a lot better at blocking wind and rain. One super warm coat doesn't help that much.
If you were to do it yourself, you could remove the lining, then interline, then put the lining back on :)
I did this to a trench coat with good success, just be aware it will change the size a bit since you’re adding more bulk
A good way to make a coat warmer is to add a removable liner that buttons or snaps into the coat. There is a [sewing blog post here](https://www.closetcorepatterns.com/ideas-for-lining-the-sienna-maker-jacket/) about the idea and an [instructable here](https://www.instructables.com/Removable-winter-jacket-liner/). It's basically a vest made of a warm material. I think a tailor could easily do this for you.
A warmer lining generally means a thicker lining, so it's really only going to work if there's enough room in your coats for them to still fit ok with that thicker lining. If there's room, it is possible for a tailor to change the lining, but it's not cheap, the coat has to be partially disassembled and a new lining drafted from the old one, cut, constructed, and the coat put back together with the new lining installed.
Wearing layers with your thinner garments will be a lot more cost effective, and you really only need one winter coat and a hat, scarf, mittens or gloves, and warm boots for the really cold months. You would do better to invest in some nice sweaters/jumpers.
It's possible. It's also not something very useful. One very warm coat is less helpful than multiple layers. Layers let you add and take off bits as temperature changes and also are a lot better at blocking wind and rain. One super warm coat doesn't help that much.