Ovechkin is scoring roughly evenly at home and on the road, so he will pass Howe in terms of home goals when he scores 120ish more home and away goals, bringing his career total to about 915. That sounds doable.
Getting another 210ish career goals does not sound realistic, that would require Ovechkin to top 1000 career goals, and only then he would beat Gretzky's home goals record.
Once he fulfills the 894 mark beating, we’ll see. If he finds himself ready for playing, why not to go deeper in his 40-s to break 1000 goals mark?
It’s a bold prediction, but if he’s ready and healthy enough and still able to feel joy of playing, why would he want to stop? Jagr didn’t, as well as some other players too.
1000 is separated from 900 by only three 30+ goal seasons, which seems doable for the great 8, even with aging considered.