We take this route almost every month with our rig and toad -- not a problem. Unless your cooling system and A/C is in tip-top condition you definitely want to take it in the very early AM this time of the year. You could also do it in the evening but need to be aware that there are no street lights and they are repaving so road markings may be iffy to see @ night. Traffic is always very light.
Earlier this week we went from Pahrump to Baker and at 7 AM it was already in the 80's. Checking the weather service today it is supposed to get to 115 in Baker and 104 in Pahrump.
If it wasn't for the temps and I really wanted to find something to do/see then I would stop at the China Date Farm and the crow (?) bar in Shoshone. If you miss these you really aren't missing much ;-)
There is a pretty good Greek place called the Mad Greek in Baker right at the 15-127 junction. We usually stop there and pick up some food to go to eat towards lunch time. If you want some snacks then in Baker is an Alien Jerky store that sells nuts, dried fruit, etc.
VERY IMPORTANT-> fuel up before you leave Pahrump. Baker is always has some of the highest prices for fuel in the area. Then, if you're heading South on 15 get off on Lenwood in Barstow and there are several truck stops including a Flying J.
2011 Airstream Classic Limited
2011 GMC Sierra 2500HD Duramax/Allison