BLE Data Logger for heart rate and HRV

Hi all, looking for hardware and feasibility advice:

Goal: Log BLE heart rate data from polar h7 chest strap 24/7 using a small module I can attach onto the heart rate strap.

User Story: -Turn On data module -Pair data module with BLE HR strap (I am not sure if the H7 strap broadcasts continuously or has to pair to broadcast) -data module records all BLE HR strap data and adds time stamp from RTC clock. -Press button to stop data log and unpair data module -Download data from data module (method is not important)

Requirements: Storage for at least 72hr of data... 1mb-512k? 72hr battery life Matchbox sized ideally.

Thanks for any guidance, I'm a novice with hardware/software and a bit overwhelmed with the processor and ble board options.