Re: can't change data directory bitcoin-core 0.19.0.1 ubuntu 19.10
Could always try installing Windows 10... and then setup the Windows Subsystem for Linux (WSL) and then once it is setup, you can try and install Ubuntu (you can basically just goto the Microsoft Store and click "install") and then try running Bitcoin Core using that. 
why should I install windows 10 and then ubuntu from inside windows? do not make any sense then I rather use windows 10
Even if I use "try ubuntu" w/o installing it and I download the bitcoin core same stuff can't choose a different location for the blockchain directory , you can try it is fast and easy with an usb3 you are in ubuntu in 5min:)