Question about spindly tomato plants. [View all]

Sooo.... we bought seeding tomato plants back before Easter, but the weather got so freakily frigid we couldn't plant them until last weekend. Now they're all spindly. They're showing some new growth on the existing leaves, but they will never flesh out like a healthy tomato plant should.

Here's my question: there's some vigorous, healthy new growth at the base of the plants. Can I just pinch off the spindly upper plant and give them a kind of reboot from the new growth at the bottom?