Cable Modem/Internet - does it go in standby at night?

We moved to a different place in Vegas this past summer and I've noticed almost every morning it seems as though the internet access needs a few minutes to "wakeup".  For instance, I'll power up a laptop or iPad and for about five minutes and I can almost never connect to the internet (WIFI connects fine to the Cox Cable Modem).

If I give up and retry in 5 to 10 minutes it is fine.  What is unusual is that sometimes I can connect to local sites (Review Journal, etc.) but not to USA Today or Google News for instance.  As though it is establishing routes outside the local metro.....

I have Mediacom and Comcast accounts at other locations and have NEVER had this issue.

Is there a "Sleep Mode" in the Cox cable modem that needs to be disabled?