Run a VPN Server on your Router or somewhere on your LAN.. Create a User/Pass for each remote device on that VPN Server, setup a DynamicDNS Service so you always know the IP Address of your VPN Server, then configure your laptops/tablets/phones VPN Clients (built in or app) to connect to your VPN Server and login when they are on a remote network..
thats the basic jist of it.. when the VPN is established your remote device is just another device on your LAN's Subnet and has access to all the hosts on your home network, from anyplace in the world that has internet.. its all encrypted, so even if your on a public wifi all your traffic is safe and secure, as long as the VPN is connected.
If a device ever gets lost or stolen you just delete that devices user account, without having to reconfigure every mobile/remote device you own.. as long as you use separate logins for each one.