Good thing you couldn't figure out port forwarding. Straight RDP port forward is kinda dangerous - like leaving your front door with a flimsy lock sitting on a dark alley. I assume splashtop is more secure. But remember teamviewer ( similar remote view program) had a major hack a few years back - bad guys were able to login to any system using teamviewer.
I used to use Essentials remote web access until Microsoft "essentially" stopped supporting it. Certificates would expire with no way to renews them. Took some learning but better solution is below:
I now use a VPN via openvpn protocol setup from my router (pfsense opensource router - great but has learning curve) to my off-site computer. Takes a bit of doing but very fast and stable. Then you can run RDP as if you were in the office over the VPN. Or if you like open AC on your laptop as if you were on the office network.
In my mind servers over the last 5-10 years really didn't get much faster. I'm waiting for the next generation of server CPUs with massive cache combined with faster SSDs and faster memory. Should make a big difference... if not held back by application "inefficiencies". JamesNT previously hinted at an explanation of such inefficiency. So I'm asking: James is the next gen server hardware gonna be worth it for us small guys running AC server and a simple domain?