LO Calc 6.3.5 Cell comment box

Can the comment box be resized by dragging the sides with a mouse?

Yes, but only for existing comments.
You can not expand the size of the box when you are entering the initial
comment text.
In a cell with some comment text select View Comment and you can then
resize the box and the custom size is retained for each cell comment
changed when saved.

Hmmmmmm.

Is there a work around to take a resized box and copy it to other cells?

One box at a time is basically worthless to me. I need to resize all boxes, as I use a larger font so I can read the comments, enter the comments, etc.

Well, when the font changes the box will grow vertically to
accommodate larger font or line spacing changes even. The width of the box
doesn't change automatically however.

I don't know of any way to change the default font setting for comments.
Which doesn't at all mean it can't be done.

It's beginning to look as if no developer ever considered what would happen if a user used a larger font, and would the result be legible.