If you're very constrained when you can travel, I'm sorry - flexibility is our easiest answer to booking problems. Apparently most Americans want to book all the popular destinations in the same basic timeframe. If you can work around that, life is easier.
We booked the Grand Flora about 12 weeks out with no problems at all; then our friends also booked their award room for the same week. But we were booking a week in February.
I would think Milan would only be a problem during certain trade show times.
Calling Marriott might be easier, if you get a good CSR. At least, they can check dates faster than you can on-line.
But, msrohud is right that being creative is of the essence. Maybe it's only one night of the week you want that isn't available? Don't expect the rep you get to think that way. You can spend some time on line doing research - see if individual nights you want are available. But I usually have good luck just calling Marriott. Good luck to you!
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