expected departure date, minus 2 weeks for dry and beginning cure, minus minimum 10 weeks for flower. I like a 3 week veg minimum.
So: if you're moving Aug 1... better hurry! 10 weeks veg, 2 weeks for dry and Start of curing, min 3 weeks of veg (more if you have less light).
~16 weeks from your move date is when you need to be On and Going. So maybe 18 weeks before you move date, is the latest you'd want to begin. But... april, may, june, july. That's 16 weeks, and we've already lost 1 from April.
Also: when judging lamps, go by "PAR." Luminance is a human-optic-subjective thing, not the right measurement to determine plant usefulness.
If you can't upgrade lamps immediately, don't worry. Just use what you got, and keep them close (but not too close). It doesn't take much to successfully finish a cannabis plant, but minimum light isn't going to produce stellar results. Just average-ish, probably. It'll still smell and feel good, just won't be all that great.
I've seen a mere 2x cxa3070 produce 'sufficiently'. I bet those 3x lamps mentioned in the OP would produce similarly (perhaps a bit less... but you'll have better spread). If you want to try, now's the time. If you wait, it'll be a scramble right before you move (or you'll have to wait until September to begin...). That will probably suck. You'll be exhausted from stressing over plants, and then you'll have to move all your stuff too! Fuck that. lol. On the other hand, you'll be stoked and motivated by having almost-ready bud. Hmm...