In which case, pretty much everyone will be unhappy.
The Leavers will be unhappy because we still have free movement and the Remainers will be unhappy because we're no longer in the EU (it'll be a "less worse" out of the EU situation).
There may be a small subset of each group who will be more happy with the out of the EU but in the EEA than they would have been with still being in the EU or "having control of our borders" but I think it's a pretty small number.
Oh yes, it's an inherently unstable situation alright. Both sides will engage in a tug of war, but this time Bremainers won't be the Project Fear, Brexiteers will be. EU immigration may reduce naturally anyway due to the combination of the drop in the Pound, uplift of Eurozone economy, rise of xenophobia in UK and fear of not being able to stay in UK permanently. This takes the impetus out of 'taking control of borders' soundbite.
If Labour gets its feces together in the meantime, HDQs their current 'leader' and if LibDems manage to make a few steps up in the next thirty months, it is quite possible it won't be Theresa May who will be calling the shots on what kind of a deal will UK have with EU after the transitional period anymore.
It's a chance to remain in EEA and even rejoin the EU in a not too distant future. A Bremainer like you should welcome it
McHrozni