One thing to note .... hotels are typically less generous with upgrades for longer stays. After all, on a 10-night stay, you only need one night where that upgrade room is sold, and they won't give it to you for the other 9 nights.

My best upgrades have come on shorter stays, during quieter periods.

What time of year are you going? Is there likely to be high occupancy during the period?

You could try to email the manager of the hotel prior to your stay to request an upgrade, but, as always, no guarantees.

Cheers,

GenevaFlyer