It will never be done. This will be the argument for a generation, at least. There is absolutely no hope of settling on any kind of end state while any of us still have hair, teeth and motility.
When we leave, if it's a disaster then we'll end up back in the EU quite quickly imo. Because people change their tune pretty fast when things go to sh1t.
If it all turns out fine, then great. We can move on to the domestic agenda.
Right now we are still in the "It will be great/it won't be too bad/it will be a disaster" limbo. At least this question will get answered after we leave, I am sick to phucking death of seeing the same arguments over and over. Everyone just seems to harden their position, at least after actually leaving then we will see what's what.