You can have a car run forever if you keep the oil up ...even if it is leaking from the upper part of your engine.
But remember the oil leaking can destroy other things espescially starter motors which are not cheap to replace.
Regularly wash the oil off at a wash station when engine has cooled down a bit.
Don't stress tooo much unless you are going thru a litre of oil a day.
All cars leak oil when they get old.
Just ensure your car isnt going to catch fire...that is a big problem.