It feels like you're missing a line somewhere in this - you talk about quitting your job, your wife getting fired, and your now-ex-boss offering you a raise to stick around, then start talking about "both jobs" without ever mentioning a new job.
So I did both jobs, the old and the new, simultaneously.
The initial plan was that I'd do it for a couple of weeks or a month. I was just trying to cover my wife's income until she found a new gig.
Lo and behold, doing two jobs simultaneously is surprisingly easy.
And Lord is it lucrative.