Don't even bother to think about replacing Johnson, unless of course, he dies. As long as he can breathe on his own, the Democrats will stap him to a chair if necessary and wheel him in to the Senate like it's "Week-end at Bernie's".
I'd rather see him recover.
Well, the truth is Strom Thurmond was very incapacitated and he continued to serve.
Just because someone has a stroke wouldn't disqualify them from serving, IMHO.
My dad had a stroke, he lost his speech, and use of one arm, but within a month, he was pretty much back to normal.
His speech came back a little slower than his physical abilities.
The question would be not one of physical limitations, but cognitive limitations.