SBS 2011 Network Running Out of Address Space - Least Painful Fix?

Hello,
I'm in the unfortunate situation of having a network running out of address space with SBS 2011 at the helm. It's a real shortage with too many network devices, not some config issue with a too small scope in the DHCP server settings. For the purpose of this question, let's ignore the why this situation is the case, and assume that major changes to the network (like setting up VLANs, moving to a new multiple server configuration, getting rid of devices, moving devices to different subnets, going IPv6 etc..) are not feasible at the moment. Also, as it stands, all is well, and there are no performance issues, just a lack of addresses. So thanks for any solutions rather than admonishing about why this situation is the case (let's just say it was inherited) since I know it is not normal or ideal.

So the question then is what's the best way to deal with this. Obviously, the solution is to switch to a larger net mask, such as 255.255.0.0 to give 192.168.1.1-192.168.255.254. But what would the best way to achieve this be without needing to manually locate and reconfigure every statically assigned device on the network, and deal with the associated fallout? I'm also concerned about breaking SBS wizard related stuff in a way that has unintended side effects in the future, and know I'll need to test anything in a VM and virtual network before deploying, but any ideas you have are much appreciated.

For instance, would it be possible to keep the current network as is, and add a 2nd DHCP scope on a different subnet for new devices then setup routes so both networks can access each other?

Thanks,
Jonathan