Could probably work, but I think it would depend on the hotel's procedures, and also the QCC website advises against this, as they (hotels) can hold your funds for up to 3 weeks.
Maybe some hotels don't like the fact that QCC is a prepaid card, and they (hotels) prefer visa/mastcard debit/visa/mastercard credit cards.
You could check in with a visa/mastercard debit/credit card for the preauthorisation, some hotels take $150 up front, and then on checkout, pay with the QCC, but have to make sure when you check out, you do ask them if (the hotel clerk) if the preauthorisation will be revered by them or automatically.
Tried with my QCC at the Novotel Auckland Airport to use it as preauthorisation, person put it through reader, but it would not accept the card, but another hotel here in Aust accepted the card as preauthorisation.
Probably best not to though, waiting 5 days to 3 weeks for the funds reversal is not good.
Buying a $1.60 or $2 daily paper and morning coffee several times a month with the QCC would put some QFF points your way.
Edit:
...fees when you use the Qantas cash funds overseas?
Hotels overseas still wallup you 1.5% for credit card surcharge, and this includes the QCC and VGW, downsides of using these cards.