https://freesewing.org/ might also be of interest. It's more about sharing novel customizable patterns than solely drafting up slopers that you then have to modify into the garments you want...
But having sewn my own clothes for awhile, this feels like "why do it the old way when we could keep what's challenging about the old techniques and introduce technological problems too?" to me. The most eco-friendly way to get clothes that fit you is to find secondhand clothes that are a bit too big, then take them in to suit your needs. And if you're growing most of the food you eat with hand tools, walking or biking instead of driving, and doing other pemie things, you're likely develop a body shape on which clothes discarded by folks who sit in chairs all day eating as much processed foods as they like are generally too large.
Then once you've taken in a garment to a fit you love, you can take the pattern from it if you want to make copies. There are plenty of articles on how to take a pattern without destroying the garment, like https://www.mybluprint.com/article/make-pattern-from-clothing, and historical costumers do it a lot on old garments too. Then you can use your pattern to make as many copies as you want, and you don't even need to own a measuring tape for the whole process.
If you're actually weaving all your own fabric, you'll probably want to sew from the types of patterns that were used when fabric was more precious than human labor. If you grew and spun and wove every square inch of cloth yourself, you don't want to waste a bit of it, so you'll do better with less-fitted garments constructed mostly from squares and rectangles than with modern cuts that waste a lot of cloth in order to take advantage of the figure-hugging stretch and drape of synthetics.
Josephine, I've inherited some bolts of wool fabric that my aunt and grandmother bought decades ago from Pendleton, and they seem about the same quality as the cloth I find at the Pendleton store in Portland, OR today. So that might be a source of old-fashioned good wool for you.