Actually I'll second the tone of Stir Crazy; I've seen some truly exceptional talents move into internal consulting roles and thrive on the challenges. If you want to keep the external MC option on the table for later then you'll need to keep in mind visible stakeholder management to prove you can still 'cut it' in external consultancy though, and you'll have to deal with the politics which you can cut through more easily in an external role - but you might enjoy that element. It is not for nothing that most grad schemes and prof dev schemes involve rotations around a business through different functions, from front line to top line: the rounded sense of the entirety of how a company it put together, its operations end to end, markets, finances and risk exposure is what makes a business leader just that. Sounds like a great opportunity and one you would do well to take.