I just hope they are at the top of the game in security so they don't get hacked. Shutting down for a long time is not a good market strategy.
to be honest and actual this is not an impossible thing. they can be hacked too. if bitcinex can be hacked then bittrex can be too.
if they are not updating in their social channel and forum thread it make it even more bad. I told this to many people and want to repeat again. never store your extra money in any exchange.
edit: just took a look at bittrex. found that the site is seemz up now.