Actually, this is great news. Both the UK and the EU have stated that hard Brexit happens unless both the EU and the UK sign off on the sane deal before 21 January 2019. This won’t happen. So, hard Brexit. The deal offered keeps the UK in the EU in perpetuity, unless the EU lets the UK go, which would only happen if the UK won a hot war with the EU. The deal offered was incredibly bad. A no confidence vote would lead to early elections, and a probable Labor victory, and an end to hopes of UK independence.
Lots of questionable assumptions there, not least that a Labour government would mean the end of Brexit. The hard left wing of Labour, which now controls the party and to which Corbyn belongs, is just as anti-EU as the right wing of the Conservatives, although of course for entirely different reasons. Corbyn in his many years as a Labour backbencher has consistently voted against every EU treaty and measure, often in defiance of his own party whips.