Lubuntu remote desktop - text is very small!

When rdp-connecting to a computer running Ubuntu with the Lubuntu desktop, you might find that texts and menus are microscopic.
This is due to the screen resolution of your local laptop.

To solve your problem, try to navigate to the following menu item:
Preferences > LXQt Settings > Appearance


Select the "Font" section (third icon from the top) and increase the "Point size" to whatever you feel is sufficient.
In my case I have increased it to 14.