opened yeast

So I decided today that I want to bottle today or tomorrow. I have a packet of dry lager yeast that I opened about 3 weeks ago to bottle my last batch. I was wondering what the shelf life of opened dry yeast is? (Kept in the fridge.) My LHBS is closed today and tomorrow so I can’t get new stuff. Normally I wouldn’t worry about it, but this beer has been sitting in the secondary for about 2 months. I’m not all that worried about infection, more about viability. Is this yeast still going to start up for me?

As long as you kept it away from O2, in a ziplock bag for example, it should last plenty long, a few months I would think. I've used open dry yeast after a month or so with no problems.