Didn't reach target FG, pitched more yeast, gravity same after a week. Should I just bottle already?

My batch didn't reach the target FG and I'm trying to decide whether to just bottle or to pitch more yeast (would be 3rd pitch).

I have a very similar situation to the one described here:

Brewed an Oatmeal Stout and the gravity did not drop as much as predicted, should I re-pitch or add yeast nutrients/energizer?

Also made an oatmeal stout, did a partial mash w/about 5.5 lbs of extract and 5 lbs of grains including 1 lb of flaked oats. I used liquid yeast (White Labs English Ale) and made a 1 liter starter.

Target OG was 1.055, mine came in at 1.050. After two weeks it went down to 1.019-1.020 (kind of on the line). Target FG for the recipe is 1.016. It got too cold at one point so I thought it might have stalled.

So I pitched another packet, waited a week and the gravity is as the same place. I didn't make a starter with the dry yeast, because there's a lot of yeast in a dry packet and it seemed like overkill for a 5 gal batch.

I'm guessing that I just have a lot of unfermentables in there which are bumping up the gravity. I added 1/2 lb of cocoa powder and maybe didn't have the best efficiency with my stove top partial mash which included oats.

I tasted it and I don't think it's particularly sweet for a stout - tastes pretty good to me for room temp uncarbonated beer.

So should I just bottle already?