Hi @RogerS49 you should be fine with a 1080ti. I have a 10 year old Dell T3600 with a 1070ti and I get “reasonable” performance out of it. By reasonable I mean it’s about as good as the Google Colab free version 
but that’s good enough for the purposes of the course I think.
I also upgraded my Ubuntu from 18.xx to 20.xx and had to do a fresh install of the whole stack, which in a way was a good thing because I hadn’t done that in a while. I did end up going the nvidia and paperspace fastbook container route though because I just couldn’t get it to install natively on my machine.
All the best.