I will be there in April/May. Have researched Stave Churches, among other sights. Here's a good web site with pictures and descriptions of all, plus a map with all of them marked: https://www.stavechurch.com/our-stave-churches/?lang=en
In the area not far from Borgund are also Urnes (Ornes) with animal carvings (looks VERY interesting), and Kaupanger, all pretty close to Laerdal. The huge Heddal Stave Church in Telemark county, closer to Oslo, looks amazing. I tried to paste the map here but this doesn't allow it. Check the website, it's got it all. Also look on Wikipedia under "Stave Church". GREAT information on their history, construction, styles, a list of all and a map with all locations.
Personally, I'd fly into Bergen, LOTS to see from there into the fjords, besides starting much closer to the Stave Churches you mention. Renting a car in Oslo and dropping off in Bergen is a big extra one-way fee. I know, as that's what we are doing, but we're in Norway for a whole month so will be doing a lot of wandering. Start close to your goal and have more time to see 2-3 churches and enjoy some beautiful scenery there, also. ENJOY!!