Li-ion Battery Shelf Life Calculation (Including Temperature)
I've found what is hopefully some relevant information over at batteryuniversity.com

Whilst I don't have any calculations it would seem that they have done some measurements of li-ion batteries





Over the first 24 hours they will already be at 95% looking at the first table. So we can assume that they are at ~95% by the time they are put into the box ready for shipping.

Looking to the second table it would seem that they lose 35% of their charge per month if stored at 60°C whilst above 60% charge. So if we do some rounding of the time up (For ease let's just say that 28 days = 1 month).  This means our 95% charged batteries lose another 35% whilst in 60°C transit. This puts our battery now at 60% charge.

So you can assume the batteries you receive to have retained >60% of their charge. I know this is all very rough estimate figures but hopefully this helps you if even just a bit.