This is going to be very challenging for you!
Good luck at using points or some points at Grand Flora. You should read about others recent experiences with this and other similar properties. I would at least try to get in there and then negotiate with the front desk. This worked for me recently, I had the first night on points, and the hotel indicated "Sold Out" for the other two nights, but when I got there they had all kinds of rooms and took my points. Beware though! Have back-up!
In VENICE, the Courtyard is a very nice hotel and only a short bus ride to Venice and the train station. In Milan, the Marriott is a wonderful full-service hotel,close to the subways, a short cab ride from the train station and the Duomo (but a $100 US limo ride to the airport). Do take the guided tour to Duomo, LaScala, and Last Supper - well worth the $50 US!
The GREAT news is, there is currently availability in early June using points including Marriott Milan, Renaissance Naples, Courtyard Venice Airport and even at the legendary Marriott Grand Flora in Rome. (It's pricey - 40,000 points a night.) The not-so-great news is w/o Platinum Elite, who can say what type of rooms you'll get.
Milan Naples Venice
You can book now for points over the phone and request that they hold off on redeeming the e-certificate. By default, the e-certificate is issued 7 days prior to arrival. Check cancellation policies. They differ by brand and location. This way you know how big a window you have if your plans change suddenly so that you can cancel w/o penalty of losing your points.
Thanks for the input on Venice. A lot of people are down on the Courtyard, but we did not mind the short bus ride. It was well worth the points and was very comfortable. Lastly, we do not need a "Spectacular' place at all, we just like the casual atmosphere of the Courtyard.
If you get a chance and want to see some great historic scenery, go to Lake Como, North of Milan. You can visit the Bellagia and see George Clooney's place.
There are no Marriott properties so we always stay at a small town called Chiavenna. There is a nice Best Western, Hotel Conradi, with great (Inexpensive) food, and a wonderful downtown. See pictures and enjoy the Norther Italian mountains!
Unfortunately, there are not a lot of Marriott's in Italy. The Grand Flora in Rome is THE PLACE to be but is very difficult to get into using points! So, keep trying!!!
I'll be going to Italy for 3 weeks in Sept - Oct. Starting in Venice at the Courtyard, then to Florence (not a Marriott hotel) with a day trip to Pisa and Lucca. When I leave Florence, I'll pickup a rental car and go to San Gimignano and Sienna for a couple of nights before heading to Assisi. (no Marriotts here either) After that, I'm heading down Sorrento (again, no Marriott) and the Almalfi coast before ending up in Rome (Grand Flora for 5 nights!).
Good luck and have a wonderful trip!
My wife and I went Milan and Venice last year and are going to Italy again in the summer. Used Visa Marriott 1-5 free night stay in Milan and service was excellent. The Milan Marriott is a nice property with a concierge lounge (7th floor but very small and limited selection - sodas, water, nuts, select cheeses). Beware though, the rooms are very over-the-top in terms of floral patterns, I'm more of a modern guy myself but to each their own. It is in a more residential area but has a pastry shop & supermarket right across the street, and a good pizza place (Napoli Ristorante) to the left of the hotel when walking out. The metro stop (Wagner) is a few blocks past the pizza place and takes you to the Duomo (must see, which is near the Gallerie and La Scala, which I recommend visiting as other people have mentioned. If you are a pure tourist like I am, you only need 2 nights max in Milan to see the aforementioned destinations and the Last Supper (recommend booking a tour to guarantee access). A must is to also go to the top of the Duomo, the views are awesome. ALso recommend Lake Como, which we did as a day-trip (take the finucular up to the top for great views).
In Venice stayed in a Westin so can't comment on the Marriott there. This summer we are staying 2 nights in Flroence (no Marrriotts there) 5 nights in Rome Grand Flora using points before going on a cruise so looking forward to it. Never been to Rome before so appreciate all the feedback on these posts. Was debating about whether to use Visa Marriott 1-5 stay in Naples but figured Florence would be best since going to Naples for a stop on the cruise.