Although I cannot yet afford one, my ideal winter coat is a classically styled polo coat, in a cashmere and camel blend.
Double breasted, full length, generous lapels, half belt, turnback cuffs, flap breast pocket, et cetera.
It is the best classic form of outerwear, as far as I am concerned.
Ralph Lauren is known for theirs, which is especially nice as far as easily obtainable RTW overcoats go.
I believe they sell for around $2,000, and it is offered either as a standard winter item or MTM.
Come to think of it, I'd like to know some more about it.
Does anybody know some more about this particular coat, and its availability?
It would be of purely theoretical use to me at this point, but very much appreciated nonetheless.
The other coats that come to mind are wool or shearling, from Paul Stuart,
and one of Loro Piana's various offerings. They have some beautiful shearling and fur-lined coats, as well as cashmere, wool, and some other more exotic cloths.
If by "splurge," you mean "spend $25,000 on a sheared navy blue mink peacoat from Jay Kos," then you should probably do it.
Post pictures, though, so that we can nitpick the fit and styling until you ultimately decide it's not your cup of tea and sell it on B&S to some poor chump (me) for, say, $350.
Finally, it may be a matter of personal taste, but I've always liked the idea of a charcoal wool-cashmere topcoat with turnback cuffs and a black astrakhan collar. That might have to be bespoke, but i suppose it wouldn't be entirely impossible to find RTW.