That sounds exactly like my experience(s). I'd change to levemir if it was available in NZ, but as it isn't I muddle along by checking my bg 15 minutes after taking my night time dose. Still don't understand why I had 10 years of using lantus without issue, and am only now having problems, but I have a big jar of glucotabs next to my bed and I'm ready and willing to use them as necessary. But it's the steepness and speed of the fall, combined with the large amount of sugar required to stop it, that differentiates this from normal hypos.