Update/interest letter length

I have a fairly substantial update letter that is about 1 paragraph longer than a page at 1" margins.

I can play with the margins, and/or remove my letter header (my name/address, recipient name/address) to get everything to fit on one page.

Is it worth making the margins very narrow? Would removing the letter header detract from the professionalism?

Basically, is it imperative that my update letter be a single page in length?