Refer: Librem5 vnc remote access
Yes, via WiFi. (It makes no difference though to the actual problem. I could have tried gigabit ethernet too.)
However someone did add a post subsequently to the above-linked topic and that post says that he found a way. Unfortunately it involves building a whole heap of software from source for ARM - so there is probably still no out-of-the-box solution and it is 50-50 whether, without detailed instructions, a random technical user could actually achieve the outcome.
Give it a go and let us know. 