Mu question Can I do an install onto a 4GB usb stick which is smaller than the recommended installation size? was closed as exact duplicate with a url to possible duplicate answer.
Currently I have very specific conditions that stated in my question. Especially that I have no hdd and only 4GB stick available.
I cannot find the solution in provided "possible duplicate" answer.
I admit that I am not so experienced Ubuntu user and working solution might be there but I cannot see it. Please help :-)