Road trip USA with toddler

We have a 1 year old baby and would like to do a roughly 4 week road trip along the Pacific highway between Seattle and California and then maybe 2 weeks relaxing somewhere.

We'd need to rent a RV and imagine it is will suit traveling with a baby as she can sleep in the same place each night and we can prepare our own food. We hope to camp in a lot of national parks, do day walks and visit some cool towns and cities.

One idea is to leave at the end of May from LA and drive North to Seattle/Vancouver? or can anyone recommend some good alternatives?

Any good ideas about cost and traveling with a little one, she is a happy baby that sleeps well so we feel comfortable about taking her.