Switching from 1tb to 20gb cloud storage - what happens to the 340gb of images in the cloud ..?

Hi - apologies if this has been asked before, I did a search but couldn't quite find the right question. 

So, I have a Lightroom (LR) account with 1tb storage. I want to change this to the plan that has Photoshop and Lightroom Classic (LRC) but with the 20gb option.

I have already backed up those files to an external hard drive, and that drive is now my 'local' storage for LR. 

My question is this: when I switch plans, 

1. what happens to the files in the cloud  - do they get deleted?
2.  what happens to the files on my external hd  - since it is linked to LR, do these also get deleted if I have the external HD plugged in to the computer ..? 

thanks, 

s/