Trivago search result for 2night Sat 16/9 - Mon 18/9 5* F1 weekend Singapore, sorted by Distance from Robertson Quay =>
https://www.trivago.sg/?iPathId=4427...&iFilterTab=0&

15-18th September then, F1 Singapore is a night race. Are you booked for 1/2/3 nights that weekend? See wiiki for contact info, be proactive to have best other options !

WOW if IC Roberson full hat weekend and hotel honours walks to other 5*'s it will cost a fortune.

IHG Walk guidelines, if they can be said to apply to early cancel notify as gainst no room at checkin time includes

1. Book guest to nearby equivalent quality standard hotel, and pay for transport between hotels
(Does not need to be IHG hotel, but yes IC Bugis is sold out, IC Roberstons can move RAs to IC Bugis with RA force but not the non-RA guests)
2. IHG Hotel to pay first night for guest at other hotel (and refund/not-charge for that first night at their hotel)
3. Provide night/points credit at IHG for that first night

Now whilst IC pays first night, even if costlier, guest needs pay for remaining nights .

Normally IHG hotel can agree good (cheaper than can get ones self) rate for you at other hotel. With F1 even if discounted, at this stage in year, bound to be higher than IC nightly rate.

Suggest you use trivago.com, search and limit to 5* hotels 75+/80+/85+ ratings, (obviously can't expect higher status eg Ritz Carlton) , then ask for IC Robertsons to put move you to hotel and pay first night.

If you have only a 1night booking, then you will not be out of pocket, and even with mutinight, total cost of
i)2nights with first night free paid by IC OR ii)3nights with first night free paid by IC ... can still be less sg$$$ than any original multight booking at IC Robertson.
(PLUS I'D ask IC robersson pick up rate of most expensive night of multinight stay that weekend, as being Event the main event night is the priciest)