Disaster recovery for Root Domain

Hi Folks

We are a Root Domain with 22 Child Domain in another location (countries) .
we have VPN between the forest and child domains All is working fine. We
have 3 DC in rootDomain (Cgroot1, cgroot2, cgroot3). I would like to prepare
a contigency disaster if my root locations disappear. It mean root domain
servers died and I want to enable another location for a new DCs root and
new VPN server and allow Child Domain continue working (rplications, etc) .
Do you have any idea where Can I found information about it ? or How can I
do that?

I will appreciate any help!!!

Liliana Bravo