I've missed it for a few nights (sometimes 2 or 3 maximum) in a row or sometimes once in a few days. And this can happen a few times a month.
Despite this, sometimes my beauty consultant even commented my skin is good when I go for my routine facial treatment.
I could only attibute this to having a stable skin. I think, for long term, if I continue to slack, it would take a toll on my skin. Better don't be lazy. I must be disciplined to cleanse every night.