Can I still save these?

They dont actually look too bad to me, Its still early.
They wont romp away just yet, but hopefully they will harden up and grow slowly but surely.

I'd pot them singly if you want hearted up lettuce in a couple of months.

Years ago, when I first started growing stuff, I remember growing one lettuce, each to a 5in pot, they actually grew very well that way, but the watering, and feeding, once they reached a decent size was pretty constant .

 

I want to do the cut and come again. I don't have much space, and italso takes up less soil.

These red/green looseleaf were started and transplanted in the same days as the butterheads. Started on February 22nd and transplanted on March 29th.

 

Hello!
The optimum temperature for the growth of lettuce is 60-65 F.
They might stand a temperature in the range of 80-85 F, but not for too long and it is very important that the nights have to be cold (something that you cannot control). But, keeping the temperatures low would be good for the plants.