Aw, never give up. You can do it with more modern stuff

My world is not flat. Yeah, sure the Silverado trail only drops 150' in 18 miles, but it is up and down all the way along. Some mile long flat'ish stretches, but mostly it undulates along. And that is the flattest route around for me ...

Everything else is serious hills in every direction but one ...

Your case sounds different. Sounds like a well thought out gravel bike will work for you (mostly), and that is a good thing