There seem to be two options - third country status (which I suppose counts as 'hard' Brexit), and remaining in EEA. The second is presumably impossible now for Mrs May, while the fomer threatens exports, since it will involve customs checks, which can be very complex, e.g. checks on country of origin of goods, food checks in special inspection offices, and so on.
But Mrs May seems to be talking about a kind of hybrid, that is, her 'frictionless' trade, without free movement. At the moment, the EU seem unlikely to accept this. But maybe down the road, there will be some compromise. No doubt the City and business in general do not want third country status. Maybe also smoke and mirrors can achieve something, a kind of EEA status which is not called that.