Anything's possible, Noir, theoretically. But considering the extent of potential out there, to trade with many new countries and businesses ... I really doubt we'll suffer, long-term. The likelihood is we'll prosper to a much greater extent than now.
As matters stand, the EU actually forbids us to strike up new, finalised, trade deals outside of the EU !!! When we get free of them, the brakes will be off.
Then, our real journey to prosperity can begin in earnest, Noir.
By the way, in case you've forgotten, the US President has offered us lucrative trade. Of course, until Brexit begins in earnest, we cannot enter into that trade. But the US will be one valuable trading source, once the EU stops interfering in our affairs !
We live in exciting times.