I guess if your critical server is simply some sort of service provider and the only data requiring security are the operating keys then your hostile location is OK since rebuilding a system and restoring a few keys ( which can be hidden just about anywhere ) is easily done. Otherwise the loss of the data could be costly. If your data is static then it would be relatively easy to stash a copy somewhere. If your data is dynamic then backups are necessary. Backups can be tracked to their resting place. So their location needs to be ( physically and legally ) secure from the threat(s). Unless you can readily hand carry the backups to the secure storage area it will need to be connected in which case you might as well locate your server there in the first place.