Moisture Sensitivity Level - More than one chip in sealed bag
Open the bag, take one IC out, place a teaspoon or two of white rice into the bag, and make sure to reseal airtight. The rice will take up most of the mosture that you've introduced with the atmosphere exchange when opening the bag. If you want to do it professionally, use moisture absorbing silica gel, but rice works perfectly (Don't cook rice or silica gel afterwards).

I've had a part which said it should be soldered within four weeks after unpacking, lying around for about a year in the open, and successfully put it to operation (hand soldering). Nothing popped off or cracked. So it can't be too critical, and maybe relevant only for reflow or wave soldering.

By the way: Why can't you bake the devices? An oven in the kitchen will probably do just fine.