Will Illinois win? 100%, will they cover 23, probably not. Illinois is a solid team and yes they destroyed UGA, but covering 23 and beating a team you are favored by 9 against are two completely different. In a game like this, the game will be around 10-14 at the half and then the game will hit that lull and the illini win by by about 17-20.
Illinois' offensive style is not the type of team you bet on to cover 23. Yes, they can completely shut down Hawaii, but intensity in games that you know are going to win are never as great in a good anticipated matchup.
Illinois 70-53.