Yeah, I've been on a periodic hunt for more like them in the last few years. There are other side projects from both of them if you haven't already heard them yet, such as Emma's other collaborations Marriages, The Nocturnes, or even Red Sparrowes to an extent. Marissa also has Mountain Home and Droneflower. Depending upon what it is you like about them, certain artists may appeal more or less, but I'd look into Agnes Obel, Anna von Hausswolff, Aythis, Darkher, Chelsea Wolfe, Daughter, Emily Jane White, FVNERALS, ISON, Lethian Dreams, Louise Lemon, Noeta, Shedfromthebody, Thayer Sarrano, and The Eden House to start.