The alternative is to trade them both when they have 1.5-2 years of control left for a haul. Tampa would do exactly this of course but I don't think this FO would. And the Jays can afford to carry a few big contracts.
Letting each walk for a second round draft pick after declining a QO is the only completely unacceptable option.
Personally I'm 100% in favour of extending both. Both could be perennial top 10-15 hitters for another decade. Heart and soul of the franchise. Those are rare.