Not a 152, but have had an 85hp Cessna 120 upto 11000' across the Alps. It took most of the way from Chambery to the Rocciamelone pass to get there.
Have also done the same in a Jodel 1050 and (much, much easier) an RV-4.
The ANO allows you upto FL100 without supp. oxygen and about half an hour upto FL120 IIRC.