I guess the first step that a successful Gove would take would be to move to join the EEA (which is outside of the EU + has full access to the single market): then cite article 112/113 of the EEA agreement to pause immigration.
The EEA does retain 25% of the EU laws and is subject to free movement, so its not ideal. It would make for a suitable transition point though - and a UK moving to the EEA would probably draw Denmark and other non-Euro users out of the EU and into the EEA.
That shift would delegitimize the EU further. Plus the EU are going to have hair-on-fire banking issues when Deutsche Bank or the Italian banks fail later this year.
I dont think we should put up with freemovement at all - it will become defacto - we can’t allow it to happen.
I don’t think Deutsche Bank or the Italian banks failed at the end of 2016