|I think you're looking at this the wrong way.|
Since you need more IP's, why not just create some new subnets and associated VLAN's and then start using them for more client connections? You don't need bigger subnets in each VLAN when you can create new ones and allow them to communicate with each other via routing.
I've never heard of anybody using VLAN0
VLAN1 should always, and only be used for your management VLAN. Which is to say, all network appliances should be on their own separate subnet/VLAN from all the rest of your equipment.
We use many VLAN's here where I work. Here is an idea of our setup:
VLAN1 = management VLAN (as per above, ONLY network appliances like switches, routers, firewalls, etc are allowed on this VLAN)
VLAN 2 = printer VLAN
VLAN 3 through 12 = clients only
VLAN 13 through 20 = servers only
VLAN 200 throug 250 = DMZ (outward facing)
Each VLAN is it's own xxx.xxx.0.0/24 subnet.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.