Quick update: the Madewell leggings I'd been stalking finally came off backorder and so I ordered them. They arrived today and the inseam on the XL is about 30". Not ideal but they are well made and well-fitting otherwise, and I got them on sale, so I will probably keep them for wearing around the house or with outfits where I'm wearing boots and socks anyway.
I want to try the Gap tall ones listed above as well as the Long Tall Sally, but I've got to wait until the new year as my clothes budget is used up at the moment.
Does anyone wear the Zella leggings that are usually available thru the Nordstrom sale as leggings under things, as opposed to exercise wear? I can't tell without seeing them in person whether they'd look too gear-like.