It's an all day trip from LV. I would say you could stop along the rim in a few areas and do some short walks, not hike into the canyon, in about 4-5 hours.
But It is about 4 hours to and from LV. So staying in LV this is an all day adventure.
You also drive by the hoover damn and can spend 2-3 hours there. Making it a long day adventure.
There is a small pass on I-40 that could cause some problems if you happen apon a storm. Also near the grand canyon it can snow. I don't know how comfortable you are driving in snow, but the people around this area driving through won't be going fast. The chance of a strom though is small.
I myself would go from LV early in the am, about 6, a duanting proposistion since I don't go to bed early when there. And plan to get back at about 10 at night. You would want to see the canyon and hoover damn during daylight.
There are hotels, in the park is the El Tovar, historic and old and not cheap. To more contemporary places, and cabin style lodging as well. In the park all the hotels are operated by Xanterra. Thier website will have info.
Also in Kingman which you pass through, it's where you go from highway from LV to the interstate, are several motels. I can recall an Econolodge and Holiday Inn, but it seems like there at least 5-10 places.