Originally Posted by
tommy_muc
Since we don't participate in any of the programmes we have to pay cash (about 4800 Euros for 4 nights) and an upgrade seems unlikely

Anyone can book through a Virtuoso TA, and at a minimum you will get valuable benefits like complimentary breakfast in addition to a good chance of an upgrade.
I have had excellent results booking through
pricesquire, who is very professional and responsive.
BTW, even if you are not interested in points, you should consider enrolling in SPG if you stay at this hotel. Points can be converted to air miles.