Have you worked with MAPS and HOTELS.com yet? It was mentioned several posts back. An amazing tool. It lets you see the rates of hotels over a specific area, and then refine by star level and other things.
If you broke your stay into two parts, you might find more reasonable rates for the earlier portion of your trip - 8/7 to 8/12 or 13. You'd have to experiment a little as the rates can start climbing a day or two before big conventions since people can choose an extra day or so just to enjoy the area. For this part you might find a hotel you liked in the very central area at a rate OK for you.
Then look to the further out areas for the second portion of your trip, since you are thinking of driving to various outlying places anyway. Just to get your thinking started, there is a lovely 5* resort out in the Summerlin area.
Maybe, if you can find the right specific hotel for the 1st portion of your trip, your daughter can get that separate TV. But tell her "tough luck" on the second portion since you'll be out and about so much she won't have time to watch TV anyway? Actually, while staying on the strip, there is so much to see and do that she might not want to spend time in the room anyway. And if you walk her little feet off during the day, she will just fall asleep at night.
Have you been to Las Vegas before? While there is absolute magic there, there also are some less desirable areas and things. I hope you research a lot ahead of time.
With your very specific room type requirements, you probably will have to book directly anyway, but the MAPS and HOTELS.com tool will make it a lot easier. I find that the opaque bidding works best when I'm traveling by myself and willing to just cast my fate to the winds and see what happens. The minute I have even one grandkid or son or friend with me, often I'm forced to book directly just to take care of everybody's requirements. A second additional person almost guarantees needing to do direct booking.