Hi and welcome to PT!
That is quite a situation you have ...
First of all, to address the 2 that have already gone under, I would recommend doing what you said and putting them away ... It seems like they have already made their decision to hibernate so as long as they were plump and healthy otherwise I don't see the harm in it ... You said that they haven't been eating and that is good ... it is best that if you DO plan to hibernate them that they don't eat for a few weeks beforehand to make sure they don't go down with food in their stomachs ... otherwise it could rot inside them and kill your turtles ... just check on them every few days or so ...
Addressing the two adults that are still awake, I would say the decision to hibernate them or not is up to you ... do you feel comfortable doing so? The fact that they aren't eating suggests that they are wanting to hibernate in the near future but the decision as to whether or not they do is still largely up to you. By no means to you absolutely HAVE to hibernate them ... especially if you believe that the move was particularly stressful on them.
If you do want them to hibernate then make sure they have completely stopped eating and lower their enclosure temps and they should take care of the rest ... If you don't then raise their temps by about 5 degrees and extend the daily photoperiod by about 2 hours or so ... this should convince them that winter isn't coming ...
It is completely normal for box turtles that aren't hibernating to slow down metabolically in the winter .. they will sleep a lot .. get sluggish ... not eat often .... this is okay and to be expected ... just make sure you don't notice any other signs of illness in them.
As far as the two hatchlings go ... I wouldn't hibernate them this year ... wait until next.
Co. is going to be too cold to safely hibernate them outside so you will have to bring them inside from now on in the winter to either hibernate or not ... A number of mine don't hibernate in the winter time.
