Go for those lettuces, Molly:) I agree with Karen. Those ws things are way hardier than traditionally grown plants. I've had ws stuff out for weeks...I even planted some zinnias out yesterday. Unless we have a really freaky weather event-and that has happened-they will all be fine. I have opened the containers for seedlings that haven't been planted yet.
I hear ya Karen on the seedling planting time...I always wonder just how many seedlings there can possibly be in one jug?! I know my neighbors think I'm nuts sitting in the garden with plastic bottles or milk jugs and a stick pricking out seedlings, lol!