Logging data with s7-1200 couple of days

Hello,

I have following hardware:

S71214C CPU, CP 1243-1 for IEC 104 and Energy meter Sentron PAC3200. My Client at very beginning wanted me to transfer data from Sentron PAC via IEC 104 to utility master.

Once we have performed that he wants me to provide data logger for couple of days ( let's say 5 days) 100Bytes. These 100 bytes needs to be saved every 20 sec somewhere. So in 5 days that would be 2.1MB of data. Here is 4MB Simatic memory card for s71200 CPU series

My alternative7second solution would be to provide small touch panel with USB stick. In that case I would store data on USB stick and read it on Touch Panel first and later on PLC. 

Do you guys have something more clever in mind?