I do not see any reputational risk, but a career one: Consulting positions are hard to come by, and there's absolutely no guarantee you'd get even an interview, let alone an offer. There are 169 hours in a week, are you sure you can't carve out a few to prepare? At the very least, I would find time to polish my resume and apply; then, if you are still hell bent on resigning, you can do so with at least the comfort of knowing some companies are interested enough in your profile to want to speak with you.
Your plan might work - but what if it doesn't? Do you have enough financial cushion to not feel like you have to take the first opportunity that comes your way? Are you ready to the possibility that you'd have to leave consulting altogether?
Bottom line - I'd strongly caution you against this
PS: Yes, I am a married father who is responsible for the financial well being of a family. You might have fewer obligations - and be less risk averse as a result. You still give me palpitations though :)