I wouldn't think it would be a problem what so ever, especially this time of year when the water temps are down compared to air temps. An overnight in the water shouldn't be a problem as the water wont get to any part of the meat other than the entrance/exit holes...the rest is protected by very insulated hair/skin etc...

ps, also takes me back to elk camp where we submerged the meat in game bags into a creek to keep them cool and free of flies over night until we were able to pack it out the next morn, no problems.