We shouldn't have to worry about any import tarrifs, as the government can directly subsidise this, and if it needs to recover the money, raise this through a poll tax levied on boroughs that were daft enough to vote leave. Not just consumer produce, but also supply chain components, or alternatively print ore money - hyper inflation may be an unfortunate by product - but if the printing money is kept off the books and circulate in brown envelopes then taht should be a problem.