Well I'm glad the poll has confirmed that you dan't get rid of that lovely kilt. I would hate to chop[ it up too, that's metres of lovely tartan and it might not hang the same if you shorten it. Plus if you actually go to Rabbie Burns dinners, then you are already all set.
My contribution will be to suggest some things to wear it with (as a mom of Highland dancers, I have seen this tartan in many combos). What are "your" colours for starters?
My first suggestions, as others, is to wear it with a white shirt. If you can't wear white, can you wear off-white or cream? Could you wear it if you had some variation on the traditional velvet vest (waistcoat) or jacket/blazer? I'd suggest navy or deep green, or a jewel-toned green or blue that tones with the colours of the kilt. (Is that really a lilac stripe in there, or is that an illusion?)
If you really can't get away with any white, would that lemon yellow in the tartan suit you? Or could you wear a dark blouse with a lace collar or jabot? (Black looks too intense for you in the pics, but if you CAN get away with black, then just bookend it with black ballet flats.)
For the more casual, keeping cozy at home, or even entertaining at home, top it with a sweater. Can you show us your bottle green sweater with the kilt? It might surprise you! Again, jewel tones or dark especially if you use a thin fitted knit like a cashmere. But you could also wear it with a fisherman-type sweater and oxfords. Or with an oxford shirt layered under a sweater...
This looks to me like the kind of beutiful classic that is nearly impossible to frumpify.
Edited: just saw your latest post. Yes to navy. And yes to keeping it this length, it won't date the way a midi or knee-length one would.