No takers.

Well, can we use physics to give us a measure of the probable maximum radius of the Solar System?
Newton's work, I think, tells us that the gravitation of a massive object will continue to be in control of its radius until some other massive object interfeers. We have not measured any objects within reasonable astronomicale distances so this is an open issue.

May I conclude from this discussion that current physics can not tell us the probable minimal nor the probable maximum radius of oue Solar System?

It looks to be reasonable.
jjw