I love burgundy and cranberry and I think you may get lucky if you keep your eyes open and watch and wait. Here is my collection. I wear it more as a colour than a neutral, but I agree with Sisi that it functions as a kind of neutral. One advantage I see of this colour is that it seems to work well (in slightly different tones) for those who have warm and cool colouring and works as well with blonde as with silver hair. Having worn it as a blonde and as a silver-haired person, I have experimented in person!
My current burgundy and burgundy adjacent capsule. Sometimes the looks I create with this are tonal, but it works....
Admittedly, some of these items IRL are more cranberry than burgundy. A coupl veer closer to magenta or plum or orchid. And one or two are more like rust or chili. But I can actually wear all of these in a mix and match way and with blue or true reds (esp. if in a pattern with white.)
Not all are solids, of course, so they aren't neutrals.
Items that can be worn in spring/ summer as well as autumn or winter include the Theory suit and the Boden skirt. The Dries van Noten pants are spring/ summer/ early autumn -- they are linen-cotton blend and have a burgundy stripe. The Aritzia pants are fall/ winter/spring (too hot for summer). The Vince silk dress (that I made into a blouse) is spring/ summer/ autumn -- not really warm enough for winter.
My thoughts -- if you want to make it a year round neutral, pick up whatever you can find across all seasons, but also look for it in patterns that include your lighter summer neutrals, until you can find what you'd like in a solid. Those will allow you to mix it in and feel as if it is a genuine part of your wardrobe.
