>complicated load balancing scenarios with virtual ip
Nothing complicated about it, this would be the route I would take. If you have a load balancer use it. That is one if primary uses, server is down, load is moved to another server; keep it in the environment indefinitely too, not just for the maintenance.
Here is a link that explains how to setup the LAN/DMZ scenario if you choose not to implement the LB.
https://www.cisco.com/en/US/products/ps6120/products_configuration_example09186a008046f31a.shtml#s11Billy