It's tough and I feel bad for anybody who's in the middle of their (MPL) training right now and doesn't know what to do.
Option ii) or iii) seems like the right choice, although, if you say that the ATPL program with the CAE is expensive, I simply wouldn't do it there if there is no benefit except for comfort.
I'd focus on the exams right now because once you've finished those, I think you have a solid base of something, without having wasted too much money. And considering you have a lot of time to do your flight training, you can then still look at the marked and decide what to do. I simply think that doing anything MPL related is the worst possible thing to do right now.
And ATPL-wise it really depends.
I've talked to a couple of people who are pilots or have friends who are pilots, and they all said that finding a job as a ready entry is close to impossible right now. They've seen Emirates A380 captains getting rejected and requirements for assessments are insane as the companies have a massive pool of ready entries to choose from. So unless you have money to "waste" or some sort of job guarantee (which I doubt), I wouldn't just blindly start flight training right now.
I'd probably just finish the exams, then wait for a year to then decide what to do, at least in your situation. Falling back on your job seems like the best option. Not only will you earn a bunch of money that gives you some more security, but you'll also be able to look at the market and have more than enough time (2 years) to complete your flight training. Plus you'll refresh your skills in your old job, which means that if aviation crashes again, companies are more likely to take you back in, compared to others who haven't worked in this field for 10+ years and essentially only have experience in the cockpit.