Note: the 28 days is for a hospital environment with multi-users/patients, multi-use. I go to 60 days often with recon. My Compounding Pharma shipped Tirz recon with a Beyond use Date of one year later, with 0.9% benzyl. Go figure.
There is a reason why labs use specialized equipment to lyophilize peptides. Other ways damage the peptide. So no, not recommended to freeze recon. Janoshik also said no to freezing, to keep in the fridge.
What if you recon all 60mg with 1ml of bac, draw some into another vial, and every 4 weeks, add a bit of FRESH bac into the original vial, to rejuvenate the benzyl. A pain to keep track off but should keep the bacteria count low as the stopper is only pokes a few times. Maybe good for 3-4 months? But really, why not just buy another 10 or 20mg kit and keep this one for later.