It's not how big it is, it's how you use it
IMHO more power, up to as much as you can use in the conditions is good, but the Nikon will have enough power to get by.
What is more important is that you have enough adjustment to take you precisely & repeatably to every distance you will shoot. Now, I don't know the specifications of that Nikon of yours, but if you were planning to shoot all the way from 300 to 1000 yards, you'll need a scope with at least 30 MOA of effective adjustment - that's not total adjustment either. you desirably should have at least 10 MOA spare after you adjust your scope to the distance that's furtherest from the optical/mechanical centre of adjustment (they're pretty close on most scopes these days).
Not only that, you'll desirably have that scope fitted to a rail with around 20 MOA of slope to it, so that your scope will be operating at close to its mechanical centre at the longest distance you'll be shooting. That will reassure you that the windage changes you dial in there are operating at full effect & not causing issues because you're running out of adjustment room.
What elevation adjustment does that mean that your Nikon should have for 1000 yard shooting? A 20 MOA rail will put your 100 yard zero around 20 MOA below the centre - probably a tad more. Add 10 MOA clearance I mentioned to ensure good functioning & you'll need 30 MOA below centre, or a total of 60 MOA elevation adjustment on the scope. Your 1000 yard zero would end up not more than 10 MOA above centre, which is fine.
How does the Nikon shape up?