Back under the lights?

[Salsamaker]

I staggered the start of my seedlings so I now have 2 batches. The seedlings in the first batch are nearly trees at 14 inches and are stretching out. The 2nd batch are stocky 7 inchers. They have had a week of hardening off in the warmer temperatures we have had in the western suburbs of Chicago. Unfortunately the forecast over the next several days calls for highs in the upper 40’s to mid-50’s with lows in the upper 30’s. The weather will warm into the 60’s and 70’s by mid to end of next week. Would you put them back under the grow lights or keep them outdoors or garage? Thanks in advance for your recommendations.