I am constantly surprised by other MRI postings that say they have been able to call the hotel directly, the PP desk, or whatever to get upgraded when using points. In my 22+ years of MR of which the last 10 were at PP level, I failed EVERY TIME to get upgraded when paying with points - even though going online to Marriott Reservations for the time of my stay would have a suite or another upgrade available for cash purchase. My luck was so bad that I converted points to $50 certificates to PAY for the room rather than use points to get the room directly. That was my only work-around if I wanted a real suite or nice upgrade. Unfortunately, the cash certificates have gone away (last I checked) and the gift cards have gone bananas on the number of points needed to convert to cash, the conversion work-around is no longer a valid option.
I wish you best of luck - based on my experiences, you're going to need it. See my post from Unusual email from Marriott Corporation
Now that I switched to Hilton, I can guarantee suites with points. Also since I made Diamond with Hyatt, I am gifted 4 guaranteed suite upgrades annually to be used in combination with points or cash.
I've had hit or miss luck with it but when there was success it was by calling the PP desk and asking them to call the hotel directly. I've spent gobs more points in this process than a room, sometimes more than double BUT it has worked. I think the trick for me was to ask them not if one was available but if they could arrange one even for elevated points. I think in the one case they basically did the points to cash conversion directly instead of me having to get $$ certs.
Anyway, its hit or miss but going into it asking to play "lets make a deal" seems to have worked best for me.
Thanks for all the feedback. I'm actually going to redeem points for one of the travel packages so I'll have the seven-night certificate. I was hoping to be able to bring a few people with me since it's for an extended period. I'll try to call and see if I can possibly pay a cash supplement with the certificate. I'll only be Gold though, so we'll see how that goes.