Silly question I suppose, but if you cut into a wheel, can you wax over the open spot aqain or even wrap it up in clingwrap and age the remainder of the wheel for a while longer?

Silly question? Not at all! I do that all the time. First I cut it in half and then one half in quarter. I peel all the wax and rewax the remaining pieces. You have to peel the wax, because when cutting the, wax separates from the wheel in some places.

yep

Same here.