I used to do this quite often. And you are correct, remote desktop software is a method to do this and generally suffers from high latency.
I chose to use the remote desktop method. I found that the Microsoft supplied Remote Desktop (RDP) had the lowest latency. I connected directly into my home LAN via a high performance VPN router (hardware VPN, not software VPN) for maximum performance and security. I also lowered the spectral display update rate to 10Hz and kept the Thetis window as small as possible. I used RDP to carry the audio as well. I was able to get total latency down to around 1 second with this method, which isn't too bad and is very comparable with the Flex remote software. For PTT I just used the spacebar, the MOX button, or VOX.
Note that the above method will require between 1 and 2 Mbit/s of network bandwidth. This is sufficiently low so that your average hotel WiFi will be OK. Also, running RDP server requires a "pro" or "enterprise" version of Windows OS.
Another method which does work but that does not give you full control over the radio is to use the
RCForb client and server app's. I've done this as well and it works quite well. I've even worked remotely using their Android client.
The two methods are not mutually exclusive. You can run both at the same time and pick and choose how you want to connect. Or you can make a hybrid setup whereby basic rig control, audio and PTT go by way of RCForb and remote desktop lets you see the spectral display and operate any controls not supported by RCForb.
Again, either way you go, I recommend making the connection over a private, hardware VPN for security. When I first started dabbling with RDP and RCForb and opened ports in my router the router logs were showing thousands of intrusion attempts per hour on those ports!