Was looking at this again and could work out well in some cases.
Was looking at hotels that around NYE are coming in at £300-400+ a night.
By booking say 3 nights at a cheap local HI/HIEX for 5-15k + $70 a night and then cancelling to get 3 x 10k points, I could get the required extra points to stay 3 reward nights for a 1/5 of the price. No amazing views out of the window but a £1k saving trumps that.
Added: Just tried this and points instantly appeared in my account
