We flew into Vegas in August, also arriving in the evening, immediately departed for Kingsmen, Az - did a very lLARGE circle by way of Grand Canyon, Pheonix, Tucson, San Deigo, Los Angelos,
Disneyland and then back
to vegas for a few days.
Its a long boring drive and t is only a two lane highway. I would really consider the leave vegas Saturday nite, even if you only drive an 1 and 1/2 out to find a hotel it would do one of three things
1. Saturday nite in Vegas may be a little costly
2. You would be cutting your drive on Sunday by 1 to 2 hours
3. If you leave yur Hotel Sunday morning by 7am, you'd still be an 1 & 1/2 hours ahead of the Vegas traffice, hopefully avoiding it and get to DL well before noon being able to check in and relax by the pool for a few hours to recoup some energy, spend a few hours at downtown disney then come home for an early night before hitting the parks bright and early the next morning.
Jump on mapquest and get the names of cities/towns between Vegas & DL, thats how i found our hotel. I looked for hotel chains that i was familiar with.
I know i'm most likely in the minority here but i found very LITTLE "family friendly" in Vegas. (I also have teens). Walk the strip and try to catch all the free shows(sirens-little racey, Atlantis, Fountians). We saw Penn & Teller while we were there and the show was great and suitable for kids also (they are at the Rio). If you dont have a hotel yet, the Rio was very nice and the rooms would sleep five easily (two queens & very large comfy sofa), New York, New York looked pretty family orientated, or as much as vegas can be.
The Hoover Dam is not far, maybe 30 minutes, and worth taking the tour into the dam which is pretty cheap, historical and pretty neat.
have a great time.