Good afternoon, Bev! I hope you'll start a condo for today with Gus' numbers... I know many of us were anxious to see the poor guy start heading downward!!
Keep a close eye on the lantus vial. While my first vial was handled horribly, I did better with my second vial, doing my best to limit exposure to light, keep in the fridge as much as possible, etc., I still only got about 45 days out of the vial. If you start noticing numbers creeping up that don't seem to correspond with where he's at, look at switching to new juice.
You may want to consider having the vet write you a script for the lantus pens in lieu of the vials when you are ready to start a new one. The pens are around $200 for 5 (about half that if you are getting it from a canadian pharmacy), and each pen lasts at least one month (some will stretch the pen until it is empty, others will discard promptly at 28 days). It tends to be more economical, and they are much easier to handle, IMHO. What I particularly like is that the pen body and cap really prevent exposure to light, which is something that allows lantus to degrade more quickly.
Hope Gus continues to show better numbers... can't wait to see what they are! have a great day!