Leopard geckos and brumation
No one else has replied yet so I thought I would
What your leopard gecko is going through is apparently quite normal. Mine go through periods like that too, though they usually go through it breifly in the early spring and late fall. During which they will only eat one or two bugs once a week or so. I figure the best thing you can do is to keep their temperatures and other environmental conditions normal and offer them food whenever they are up and about and ready to eat. Other than that, unless you want a crabby gecko, you should leave them alone until they start to show normal activity levels again.
Hope this helps. Good luck.