I think we are in agreement. They could do it if they redesigned the rocket using modern engineering techniques. I don't think they could take an old design and build it today, though. Especially not quickly or cheaply.

As for how long it would take to redesign and build an old rocket, I have no idea. NASA doesn't seem motivated to do anything quickly these days. I think they opted for a new design (SLS/Artemis) with more flexibility for advanced missions, not just to the moon, but to Mars as well.