I realized there's not much about our pfSense on this blog and I guess the main reason is because they have been working very well for us. I have run across one issue twice now so I'd like to document it so I remember it in the future.
When changing the local network and reconfiguring the VPN to start working again, it is not enough to just change the settings under VPN -> IPSec ->Tunnels. I'm not sure what this is about but you must also go under Status -> IPSec -> SPD and remove the old network < and > otherwise the tunnel will not startup. You have to do this on both ends (the local and remote pfSense).