I'm sure you should be concerned.
If it means you'll be unsure of blood sugar levels whilst you're asleep tonight, it could be very serious.
You could stay awake and keep checking. But of course, you may fall asleep inadvertently.
The best thing I can suggest is that you don't want to be on your own, with no-one to check up on you if you do go hypo.
I once made a similar mistake: I injected 11 units of Novorapid instead of Actrapid. (The former has a far more rapid effect.) Fortunately, I realised immediately what I had done. And I rode it out okay.
I avoid long-acting insulins precisely because I am very anxious about going to sleep at night with any significant amount of insulin active within me.