How low can you go?

After a late night with some extremely poor food choices - I knew I was going to up for a high at some point of the night - but I didn't expect to wake up at 3am with a reading of 20.2 (no ketones thank goodness). I corrected and upped the basal by 20% only to wake 5 hours later with that horrid sluggish feeling and a 12.4-huh? 

Ok so corrected again - had breakfast and jumped on the bus to work. 9am comes around and I'm now rocking a 2.2..... It's going to be a long day people.