Yep, he hasn’t thought it through (and he admits it).
// I don’t know the logistics of how it would work. You would lose some people, but at the same time you’d up the price a bit. It’s the price of a cup of coffee a week at the moment. If you put it up you could help older people, or those that can’t afford it.” //
If the BBC went to a subscription/advertising model of funding, it would not raise a fraction of the licence fee, so services/channels would have to be cut.