Not sure I can agree with you on this one Jimmy, you may have just been lucky. Insulins will crystalize when frozen and break down the basic protein of the drug. Once thawed the composition of the insulin changes, and while it may not harm you, I don't believe it will do much good. This is particularly true with basal insulins, or long-acting ones like Lantus or Levemir. But I suppose if we're facing Armageddon, what the hell.
For recombinant DNA insulin, Humalog, can freeze and use. I can tell you that based on first-hand experience. Froze Humalog pen for a month, and used it. Kept very close track of blood sugars to make sure it worked. I had original Libre at the time and measured every 15 minutes all day. No problems.
Kept very close track day 2, no problems. After that, did not bother with anything other than routine checking until pen was done. No problems.
Oh, and keep refrigerated, will last a loooooong time. I use my insulin starting with the oldest. The only problem I have ever had is with the functioning of the Novolog Humulin pen itself. On occasion, when the pen is old, it gets sticky and does not deliver the insulin cleanly.