That IS a big adventure, nice! And no problem with the hijack, I'm up for motorcycle talk anytime
I put around 10-12K per year on the bike (Honda VTX 1800) and maybe 3K/yr on the car. If it's not raining or below freezing, I'm going to take the bike every time.
I'm fortunate in Texas we have an option to buy car insurance by the mile (milemeter.com). Saves me big for insuring a car that mostly just sits in the garage, I pay around 11 cents/mile, you buy miles in 1000 mile increments, so it usually runs me about $330 per year for full coverage, including uninsured motorists coverage, which came in really handy about 3 weeks ago, resulting in a "new to me" Solstice now sitting in my garage. Just waiting for my broken ankle to heal so maybe I'll even get to drive it one of these days!
My wife rides her own bike too, we take a long trip every summer. Last year it was Tail of the Dragon, year before it was national parks in Utah. This year we're splitting it up, one week in Texas' Big Bend area, and 1 week up to Mt Rushmore. We've never made one as long as the one you posted about... not in one sitting... That's probably going to have to wait till retirement. We take it pretty easy, lollygag along on back roads, stop and look around a lot, usually around 200-350 miles per day, occasionally might hit 500 or so, especially the first and last days of the trip...