Undercarbed beer recovery

So I have an IPA whipped up from a kit. I used 3/4 cup corn sugar dissolved in 2 cups water, added to my bottling bucket and went to town, its now 3 weeks later sitting in a warm spot, and 5 days in the fridge and there just doesn't seem to be enough carbonation to my liking. I have a get together tomorrow and will serve it (its still good mind you, I just like more carb) Would taking whatever hasn't been drunk, popping them open, dropping in a priming drop and recapping and placing in a warm spot again work or would the temp change and opening be all she wrote for tasting good? They are in 1L grolsch type bottles. Thanks

Sure, that'll work. I recommend the Munton's carb tabs, you can add one or two of those.

You need to send the WHOLE batch to me for some professional analysis! I'll report back what you could have done

I dont know. If they are already a little carbonated and you add more sugar. I can almost guarantee you that the will be way over carbed and you are taking a risk of contamination and oxidation. I guess its completely up to you but i would just drink those bad boys and note it for your next batch.

Imma take a few bottles and give em a carb tab and see what happens. Ill keep you posted.

And dont worry Kahluaman, I have very detailed notes so sending the batch wont be necessary