The big unknowns are what kind of deal with the EU does Labour want, and what kind of deal will the EU accept, and neither will be known until there have been a lot of negotiations -- which at least can seriously start now that Burnham has basically said the "red lines" are gone and anything all the way up to full EU membership will be considered. It's unlikely that we'll get as good a deal as we had before, but not impossible -- IIRC at least one EU leader has said this might be on the table. It all depends how much the EU wants the UK back in, because Brexit has weakened the EU especially given the current global political climate, specifically Trump's special brand of insanity as well as Putin's. But Brexit damaged the UK more economically, which puts us in a weaker negotiating position, especially on trade because a much larger fraction of our external trade (around 50%?) is with the EU than theirs is with us (around 10%?) because EU GDP is about 5x bigger. In other words we need the EU more than the EU needs us, which is not a strong position to be negotiating from... ☹️
