Planning Out Subnet Expansion

Hey everyone,

I have a pair of VDI networks in my environment. Each network sits in a different data center. For example 10.1.0.0/24 is in data center A and 10.2.0.0/24 is in data center B. Recently, we have started to expand the VDI network past 230 devices an naturally each environment is having issues with the DHCP pools and leases. At first we started reducing the DHCP lease time, but eventually we grew past 230 desktops in each subnet, so naturally I think it's time that I expand the networks. Each subnet is bound to corresponding/matching VLANs in each data center (let's say VLAN 10). There's a couple different ways I could skin this cat, and I am looking for opinions on the best/easiest way. Here are the options that I am thinking about:

1. I could simply create a new subnet in each data center. 10.1.1.0/24 and 10.2.1.0/24 are both available. This would require me to make a new gateway (gateways are on our firewalls), a new DHCP pool (AD integrated), and to update some firewall rules for the new subnets. I would also have to create new VLANs.
2. I could update the subnetting to expand the available hosts in each subnet. I could update 10.1.0.0/24 to 10.1.0.0/23 and update 10.2.0.0/24 to 10.2.0.0/23. I wouldn't have to create a new gateway, but I would have to update the information on the firewalls, switches, and VLANs to support this.

The caveats to method 1 is that in my VDI software, I would have to create a different pool of desktops as the new network would merit a new distributed port group. I don't think I have the ability to say VDI pool X can use multiple distributed port groups. I would also have to do a bunch of heavy lifting at both the firewall level to create new objects, new ACEs (for logging), and new gateways. I would then also have to create new VLANs on the switches and trunk the new VLANs down my UCS uplinks to the blades.

While I would still have to do some of this legwork with method 2, in most instances it's simply updating the networks to reflect a /23 instead of a /24. My only concern is that I've not done a lot of networking in the /23 space with gateways and stuff. Usually in a /24 my gateways are at .1 and I would guess that this would still be okay, but then does that mean an ip address like 10.1.1.0/23 would be a valid host address? Could a computer/VDI get 10.1.1.0/23 as a DHCP'd address?

Any insight on this would be great. Thanks in advance for your thoughts!