Mid Nov can be very good and on average, I'd say better than the spring. California is a big place, so I don't know what you mean by the 'national parks in California'. Redwoods, lava beds, Death Valley, Joshua Tree. If you are in the parks for Thanksgiving, so will be everyone else. Yosemite is hugely popular. Death Valley too. The week or even the day before can be quiet. Redwoods are very nice at that time and some color left. Most of the leaves that will be left will be a few grape leaves in the Salinas valley. The are predictions of El Nino, and we have had some early, albeit light, rains already. Rain doesn't usually hit hard until later, however, so if you're betting, go with good weather mostly. I think Tioga pass (Yosemite) closed Tday weekend last year. That is a bit late. Usually closed by Halloween. Lassen is always closed.
Basically, the deserts will be fine, but no color. The Sierras will be cold and nice and not much color. The north coast will be very nice, a little color, but chance of a storm. Anywhere within driving range of SoCal will be busy for the Tday weekend.