Then there is the 155k wide C/2014 UN271 (Bernardinelli-Bernstein) comet that could also get kicked as it approaches the gas giants and come this way eventually. Just like the 10K strike was not alone so perhaps these will not be alone either in striking the Earth. And who knows what smaller, undetectable rocks are traveling with them?
Gigantic Comet Approaching From Outer Solar System May Be The Largest Ever Seen
https://freerepublic.com/focus/f-chat/3999373/posts
It should put on quite a show, even if it misses us (which is somewhat likely). Impact would be a much shorter set, but more spectacular. ;^)
Alterations of direction by any of the planets are fairly well predictable for several cycles. That gives us lots of time.
I’d be more “worried” (more like a Spock-o raised eyebrow) about a tiny deflection way, way out. Say, a house sized rock passing by the comet in the Kuiper Belt. Then we have only the time between actual detection of the change (maybe at Neptune’s orbit?) and a potential Earth impact, to act.