Yes we'll colonise Mars at some point. Unlikely terraform it in any meaningful way in the next 500+ years, if ever. Going to Mars and uncovering it's history is important, even it seems a bit sci-fi.
The moon will almost certainly be used as a bus stop for solar system travel, and manufacturing off earth. People will live there for short stints.
We'll probably even end up mining raw materials from relatively nearby asteroid belts.
I reckon the human race has got at least another 50,000+ years to run, notwithstanding any kind of species ending asteroid. Even then we'll probably survive and thrive again. We'll survive more world wars, and even partial nuclear decimation. Humans are way too resilient.
We won't even fully run out of space, as population growth will eventually slow down once the third world becomes more developed. We'll probably start to live naturally to 120 years+, and finally be able to turn back the clock and live lives of 1000s of years.
It's possible we may end as a species as we know it, as we move more towards technology augmentation. Sounds a bit Borg, but we're already 1/4 the way there.