I have driven down the route you are thinking about. It was a very nice trip. We went in September and the roads were perfect. I have no idea in April. If it were me (and I drive in the snow in North Eastern Oregon, even to Tri-cities) I would go up I-84 and go down I-5. Because 97 between Lapine and Klamath Falls can bet bad even late. ( I lived in Lapine) I think the only place you might run into trouble with snow. But don't take my word for it.
I think a great resource would be
www.weather.com and then type in different towns along your route and look at the at the averages and snow/rain fall.
I had my Mom with me, however I did all the driving and it wasn't bad. We had a great time with the kids. We wanted to see it all so we took our time going down and then straight back up I-5 when we were tired and ready to be home.
We stopped in Crescent City for the night so we could see the redwoods, Then north of San Fran, spent the day touring and then stayed south of the city. We also went to the Jelly Belly factory, I don't remember exactly where that was but, it was fun and I love Jelly Bellys. Then we headed over to the coast to 101 it was beautiful, BUT SLOW!!!
It depends on how much time you want to spend. Coming home we drove 2 long days and made it just fine.
I think you would have a great time.
Be sure and post a trip report when you get back.
PS I didn't realize there were so many of us in Eastern Washington/Oregon. We should plan a get together and swap stories, ideas and info.