I had a similar situation on an Infiniti a few years ago. I tried to milk the original tires to the end but didn't make it. I wished I had changed them out earlier. It all depends on how much tread you have left.
GONE: 2012 BMW 550 M-Sport
2015 Audi A7 Prestige
2014 Lexus GS350---Wife's car
2013 BMW 1600 GT---2011 Kawasaki Ninja 1000---2012 Ducati Panigale