You'll find the latest updates in the link below. Most of the roads you are talking about are closed - even the paved road through Grapevine Canyon, location of Scotty's Castle.
If these washed-out roads were maintained by a Nevada county government the roads would have been repaired within a week after being washed out. But we're talking the Federal government here...it will take a couple years or so of bureaucratic red tape before anything is done.
Actually, from my experience with roads in the National Parks in the western states, I think the prevailing sentiment of National Park management is to close as many roads as possible and do minimal maintenance on the rest.
www.nps.gov
Considering that DVNP resides mostly in CA, you're right about NDOT not doing squat. The park service is working on critical infrastructure and main thoroughfares first. INYO county is busy with other repairs and has been working with NPS to ensure roads with MOAs are open; however NPS personnel are working diligently to clear roads again. Red Tape was removed after this summer's late storms with massive influx of relief funds, I don't know where you're getting your misinformation, but the park has multiple crews from several other park units working on roadways. Dirt/unimproved roadways are way down the list, otherwise for both DVNP and INYO.
Conditions are always changing and after I hit post on this it will change again because there's a storm hitting currently.
4x4 & high clearance required pretty much everywhere at the moment away from pavement.
Death Valley - Big Pine Road is technically closed, along with signs, from Ubehebe to SR 168. However, Eureka Dunes is accessible. Eureka Valley Road between dunes and Ubehebe rough.
Racetrack is accessible (degraded) from Ubehebe. Road may be garbage after this week's storms.
Hunter Mtn Road had a bad washout at Lost Burro - heard 4x4 are making it.
Lipencott is passable - it's in normal condition.
SV Road is passable - extremely rough shape. N. Pass has snow (chains are a good insurance policy)
Steel is doable, but rough in SV above the upper spring. Steps look to be in okay condition. Silt pan in Eureka is silty - muddy after this week.
If you must go, be prepaired to 1) Turn around; or 2) deal with the conditions.
Source FB posts, various DV Forums. Experience in past 3 weeks on quick trip.