I love the idea of your first-born being named fashionista-ta, so now I must try to help
Seriously, I'm very sorry about your lost luggage. It's happened to me before, and they did eventually find it, so that may still happen.
I would recommend that you go with separates all the way, which is always my strategy at any number of pieces. Boden might be a good source for you ...
1-3. So I agree, of course you must have a coat, scarf, and gloves--and perhaps a hat or earmuffs as well. A whistling wind always gives me earache. Maybe you can buy a wide scarf and put it over your ears as well.
4. Agree with black trousers, I had a wonderful pair I'm still in mourning for that lasted me 10 years. They were wool gabardine ... and no waist, so they stayed with me through all manner of fluctuations ...
5. Tweed jacket
6. Sweater
7. Skirt--a long woolen one if you like them, otherwise shorter
8-9. Agree with cotton knits for layering--maybe henleys? Long-sleeved may be your best bet ... One light, one dark.
10. Boots are good, oxfords would be an alternative and perhaps not as pricey. I had a pair in college that I loved (tobacco brown).
*** And underwear--it doesn't count when listing

Gap Body is great. You can get by with the bra you were wearing if you have to
I assume you had a bag you were carrying when this happened??
Good luck
