Analysis by O'Brien and Pech for the EU Law Analysis blog suggests that, whilst Article 112 of the EEA Agreement is an option for restricting freedom of movement, it is unlikely it'd be used as it would likely result in counter measures:
Assuming that the UK aims and is able to remain part of the EEA after its eventual exit from the EU, triggering this provision with the view of limiting EEA labour immigration to the UK would not however be cost-free. Indeed, and to the best...