How long in primary for Russian Imperial Stout

I have a Russian Imperial Stout thats been sitting in primary for about 3 weeks. All visible signs of fermentation stopped after about 2 weeks. I'm eager to get this one bottled and age it in there to free up my one and only carboy. If I'm aging for 4-6 months in bottles can I get away with bottling it after about 1 more week (total of 4 weeks in primary) Or would it be worth it to give it 6 weeks total in primary?

I'd go to either a secondary or bottle it now. Since it's one that you're gonna age anyway, might as well free up your vessel.

Have you tasted it? Or taken gravity? May want to do that just to help your decision. If the gravity is above 1.030, definitely do a secondary to rouse the yeast and get it down a little bit to avoid bottle bombs.

For that one, I'd do 4 weeks (total) in the primary, cold crash for three days and keg or bottle.

And...as just advised, check the gravity!

I agree with giving it another week, but I would skip the cold crash myself, after that much time I don't think it's necessary. JMO