You can VPN home and use remote desktop at near local performance.
You don't need to plan your data usage. Worry whether you have the files with you.
At least that's what it means for me.
I have fiber at home. About 50/50 Mbps goodput and 15 ms latency to home VPN using 4G. Remote desktop is pretty fluid. While I can notice the extra latency, it's not a problem in any way. For example Bluetooth mouse latency is worse.
Even full screen WebGL/CSS3/whatever web apps and full screen web video work well.
Some tips: Don't use any TCP based tunneling or VPN solution, like ssh or OpenVPN over TCP. They're bad for interactive use.
Measure, mobile devices have different 4G performance profiles, and that includes latency. You can have up to about 5 ms latency difference between a new flagship model and some low end 4G phone.
Desktop applications other than the browser tend to be less demanding.
Although games are not my thing, playing PS4 games remotely works also very nicely on a Macbook over 4G. Just need to have a PS4 controller and a USB cable. It just works. Very near to local performance. There's some kind of NAT traversal, so you don't necessarily even need to use VPN.
5ms shaved down to 1ms (one-way) with decent fiber could take my ping to Google DNS from 23ms to 15ms, that's going from Boise, ID through Seattle, WA all the way down to CA where the Google DNS server I am hitting is located - a rather considerable savings.
However ergonomics is a different matter... Touch screen is pretty bad for desktop usage.
Android devices let you connect a USB or a Bluetooth keyboard and mouse. You get even a mouse pointer last I tried. Although not using it like that in everyday life. It's more convenient to just use a small laptop.
With iOS Apple's Bluetooth keyboard works. Other input devices didn't work, or at least I couldn't figure out how.