It will be different.
The following comments are sweeping generalizations, and do not apply to individuals. Any given individual could be the opposite of my description or expectation ...
My experience is that undergrads are less focussed, harder to engage, demand more instant feedback, and lack motivation. They are are also more willing to learn, less indoctrinated with how things "should" be, and more adaptable.
My experience is that post-grads are more focussed, better motivated, clearer in their objectives, and more able to look at the big picture and delay gratification. They also tend to have more knowledge, and perhaps becuase of that sometimes they might feel that they know better, and not really believe what you tell them.
My expectation is that your approach will need to adapt, but that anyone who comes to you to learn should be able to be taught. But do you want to teach them? I don't think so. I think that any entrepreneur that has a chance of succeeding won't be taught.
You need to give them the opportunity to learn.
Patrick White: 'I forgot what I was taught. I only remember what I've learnt.'
B.F.Skinner: 'Education is what survives when what has been learned has been forgotten.'
Confucius: Tell me, and I will forget. Show me, and I may remember. Involve me, and I will understand.
But in the end, whether you stay teaching the undergrads or leave to teach the postgrads depends on how you feel about the opportunity to change.
Can't you do both?