Ridge Merino is another company that sells a heavyweight wool 3/4 length baselayer and they were 25%off recentlyI like merino wool leggings as a base layer. I have old ones from Icebreaker. I haven't tried the new versions.These brands sell wool leggings. They are around $100-120. Black Friday sales are coming up, and many start well before Black Friday. Justenablingsaying.
Ibex
wool&
Woolx
Simply Merino - a Canadian company that ships to US free
The higher the wool % and thicker weight, the warmer the garment.
There are more companies that specialize in merino wool products, most would have leggings.
I love the Stio Fernos knickers, but don't consider them super duper warm. I'm an East Coast skier, and my thighs get cold easily. I always wear insulated ski pants, and I wear the Fernos if it's going to be in the 20s. If the high is in the low teens, I usually add a thin merino 3/4 length base layer under the Fernos. If it's single digits or colder, I'm in insulated ski pants, wide-legged fleece pants that can stretch over my ski boot, the Fernos, and a thin merino 3/4 length base layer. It's ridiculous, but sort of works.
ushood.com

Also, check out https://www.woolly.clothing as they had a similar sale on merino leggings. Love their pocket yoga pants.Shopping FYI- Sierra has some 3/4 length 125 weight merino (85% merino, 15% nylon) leggings from Artilect right now in all sizes (xs thru xl) for only $35.