There are a few ways to get to Las Vegas. The complication is using one of the passes through the mountains. We've decided to follow a northern route. Something like the following
Day 1 I-270 N into Maryland I-70 W into Pennsylvania I-76 W — somewhere in Ohio we'll stop
Day 2 I-76 W to I-80 W through Indiana into Illinois I-90 W I-94 W — somewhere in Illinois we'll stop
Day 3 I-90/I-94 W into Wisconsin — I'm not sure, but I think we'll stop somewhere here or perhaps right when we enter Minnesota
Day 4 I-94 W for most of a day, stopping again in Minnesota
Day 5 I-94 W into N. Dakota, stopping somewhere there, if we can find something.
Day 6 I-94 W some more into Montana. Ideally, we'll stop near Bozeman. We may take an extra day here. It will have been a long week.
Day 7 I-15 S into Idaho, stopping somewhere.
Day 9 to I-15 S into Utah, stopping somewhere. With the caution that this can be mountainous and the road may be closed. Follow I-15 S through Arizona and Nevada.
This is not ambitious. We're planning for six-hour days. Unless cellular totally fails us, we'll be booking cheap hotels along the way. It's always difficult around the 5-hour mark to start locating a place to stay.
The complexity here is CA's parents went on an extended camping trip across the country when they were first married. I do have my lifetime senior pass for the National Park Service, so we have that option. While I'd prefer motels, I may be disappointed searching for them in the remote parts of the west.
This isn't quite the same as moving Red Ranger down the ICW. The boat is spacious and comfortable, and we could drop the anchor anywhere the water was deep enough and we could get out of the channel.