More than I'd like them to be, that's for sure. If you want a 100% predictable deadline for humanity, it's in about ~150 mln years when the Sun heats us up to uninhabitable conditions. Sure, sounds like a lot of time, but compared to what we could extend that for, settling for that would be selling ourselves short. After all, how do we know we're not the only shot at sentient life in the Universe? The Universe still has questions for us to answer and dying prematurely may leave those stones forever unturned