The Vegas Area has good camping, biking and MAN stuff to do! the links below take you to three different riding areas. You can Mountain or Roadie ride. You can also take a day trip down to Sedona, AZ. It can be chilly or in the 60's depending on the weather gods. If you camp at Lake Mead you are in the middle of Bootleg and River Mountain Loop. Boulder City is a non gaming town (the only one like it in NV.) It also has great golf. There are cheap hotels along Boulder HWY (Hwy 93/95) mainly in small casinos like the Railroad Pass or Fiesta Henderson.
http://www.bootlegcanyon.net/
http://www.rivermountainstrail.com/
http://www.rivermountainstrail.com/
Depends on your definition of "mancation" there is always "Vegas Baby!" Many men have lost their innocence in this vicinity. But it can also be a great adventure. the weather is usually moderate.
Phoenix is usually about 5-7 degrees warmer than us. The Black Canyon Loop, Sonoran Trail, White Tanks and South Mountain Park have incredible biking.