Julia: going to 4K a day terrifies me. I'm bumping up to 2500/3500 and I'll see how that works. Maybe down the line I'll go to 2500/4000. My game plan is to fill the gaps with cheese right now. It's high calorie, fair amount of protein, and easier to find raw, grass-fed and/or organic than meat. Once I get back to Chicago I may reassess that.
Don't eat until it hurts, don't do GOMAD, just steadily increase calories until you're gaining weight steadily. No reason to take extreme measures.
So in short: this is possible, I just need to eat more and use progressive overloading?