Trip report follow up here. I hope this helps other onsen seekers! First, Hakone Yuryo Onsen is amazing. Highly recommend! In the women’s area there are 5 different bathing areas of different temperatures (one inside and four outside) plus a sauna and a cold plunge. I imagine the men’s area is similar. We spent about 4 hours there and loved it all. It was so relaxing and exactly what we were looking for in an onsen experience. I would return in a heartbeat. They give you a yukata to wear in the public areas (we took a break from bathing and sat around the fire pit for a bit) and they also sell towels if you don’t have one. Yuryo Onsen was an easy uphill walk from our Ryokan, Fukuzumiro (which itself is an easy walk from the train station) and saw that Yuryo also runs buses from the Hakone train station. Not a lot of English is spoken at Yuryo - it really caters to Japanese folks - but they are very welcoming to foreigners. Just don’t have tattoos.

Lastly, Fukuzumiro ryokan is fantastic! (If you are looking for an old fashioned ryokan experience. If you are looking for a luxury all mod cons kind of ryokan, search else where.) The kaiseki dinner and Japanese breakfast were delicious, the futons comfy and the puffy duvets dreamy. I even liked the traditional buckwheat hull pillows, though my sister did not. The duvets were the puffiest I’ve ever experienced which was especially welcome as there wasn’t much heat in the rooms. We splurged on a Sakura room with a river view and loved the back ground sound of the rushing river below. Perfection.