[header] How to be a " homeless " backpacker in honolulu [title] Find alternative accommodations. [step] Hostels and backpacker inns are not cheap (and motels don't exist! ). You may want to consider camping to avoid blowing all of your budget on lodging. 
Even in the middle of winter, oahu nights are warm enough to sleep in with a 0 degree sleeping bag or a blanket. The island has a campground on the north east coast that sells camping permits.