I have a 5 night (Sat-Thur) reward stay booked @ Myrtle Beach Marriott Resort & Spa at Grande Dunes in late September. My wife, two toddlers, and I have the cheapest room booked--and I'm just fine with that. But, it would be nice to get an upgrade if available, e.g. an ocean facing room would be spectacular. What chances do I have, and what is the proper etiquette/technique/protocol for doing so?

I'm plat. I'm at 87 nights this year so far, and I'm currently staying in a Marriott property. I don't know when I'll be going home. I could be past 100 days by vacation time. I don't know if any of this matters. Any other info that would help you answer the question will be gladly provided.

Thanks in advance.