Systems Management

I was wondering if anyone else is using Wake on Lan rules in a large scale and if so, they could share any best practices.

We prefer to do patches at night when staff is not around but cannot guarantee the computers are on and awake, so we thought to send WOL packets to all of them and then schedul patch deployment 5 minutes later.

The process works but is extremely labor-intensive because the WOL rules won't allow wildcards in the destination (computers to wake up.) We have a working solution by using IP addresses and creating rules that cover all the IP addresses in an area, then using the rule's "map IP to name" ability, can get all computers to wake up. but it was a bear creating 20 rules (each rule can only have a maximum of 99 computers to wake up) and since we use DHCP we have to manually go in periodically and remap the IP to Name for each rule.

Has anyone else used the system? Is there a better way? this works but I am very interested in some ideas.

Mark