We have stayed in a nice park in Boulder City, very quiet and a lot less than on the Strip. It is 20 minutes to the strip and it is 30 minutes or less to the Dam and Lake Mead.
You won't have a lot of time but Valley of Fire SP is not far and is also a wonderful place to spend some time.
There is plenty of open BLM land for boondocking if you are so inclined. It really depends on how much time you need to spend in LV. Our visits in the area are devoted to spending as little time on the Strip as possible while seeing the shows we want to see. We are not gamblers so much of what is there is a turnoff for us.
The I40 route is the most efficient for time and fuel.