Active-standby controllers with same IP

I have several mediagateways served by one mgcp controller. I need to put another mgcp controller as a standby controller. When the first one will be off by any reason the other must be activated and start to process mgcp connections. The two controllers will be on separated buildings to increase fault tolerance. Controllers and mediagateways are on different networks with several routers in-between.
A way to do this is programming one IP to each controller and when the active goes out I will have do program the new address on each mediagateway, what is time consuming and let the user without service for awhile.
I am thinking to use the same IP on the two controllers, putting down the standby controller interface. The problem is that I can’t have the same IP existing at the same time on two different points over the network (routers connecting to the controller have to know its IP address).
I am thinking to use VRRP or HSRP protocols on the routers to use a virtual IP address, so when one controller goes down, the second router should direct the packets to the standby controller. This will avoid reprogramming IP address on each mediagateway.
The problem is documentation examples about VRRP or HSRP shows the two routers on the same LAN – and in my case they will be completely separated.
VRRP or HSRP will work on these conditions? Is there another way to accomplish this?