Router Freezes After Several Hours

I do have a support case open, although they seem to want to call me on the phone instead of replying by email. That's fine, but it seems very counter productive because this issue is "solved" by rebooting. I'm sure tonight they will call me, reboot the router, talk to me for the 10-15 minutes it takes to reboot and verify it's fine, and then assume success and hang up. I'm not looking forward to this, but I'll go through the steps.

I wish they would tell me what they'd like me to do, I could do it immediately now and then maybe 6 hours from now when they call me I can more confidently say if the steps taken had helped or not.

I don't understand what this thing is doing, maybe it's not renewing the DHCP leases or something.  When the issue occurs there is nothing you can do from any client (hard wired with cable or wireless) that will bring it back to life. You can't even connect to the SSIDs and the wired connections get no throughput until the thing gets rebooted.