You can meander along the Seine, crossing it on free ferries. The rides are only a few minutes long. You want to cross toward La Bouille for the view of the charming small town, and you want to cross toward the Abbaye of Jumieges.
We meandered through this area for half a day. We started at the panorama at Barneville-sur-Seine, which is technically along the Seine, but very high up; it's a hang-gliding site.
Driving through the Forest of Brotonne, we saw a line of wild boars crossing the road. There's another panorama along here, a short walk from the road.
We stopped at the interesting headquarters of the Parc Naturel Regional de Boucles de la Seine, a prosperous former farm with all its buildings intact, including the bake oven and cider press. We are big fans of France's natural regional parks.
We parked along the Seine and watched the tide roll in.
An off-the-beaten-path very small village, Vieux-Port, is along the Seine. Very charming little place whose houses have thatched roofs with irises on the roof ridges; their back yards run right to the river.
I just came across this website listing lots of panoramas.
https://en.visiterouen.com/panoramas-of-the-norman-seine-valley
Either there weren't any open restaurants that day or they didn't grab us, so we just found a bakery and bought sandwiches and goodies for our lunch.
I think this would make a relaxing parenthesis between the busier, more crowded places you'll be visiting.
Have a great trip!