Both can survive cold water. It is TShad that have winter die off at about 42 degrees. The question of if they can survive LMB predation is all a question of numbers. In some large lakes they are a primary forage fish. GShiners do not reproduce enough # in smaller ponds so you would have to stock a whole lot more to establish a sound population. GShad can reproduce in # but they have IMO serious problems with their size and ability to take over a pond by their ability to suppress spawning of other fish as well as themselves. They can get to big for all but the largest LMB to feed on and take up a very large % of a ponds carrying capacity. Unlke BG most people don't want to catch GShad and/or eat them either.