Your best bet is probably to make your own.
Find a high quality NVMe drive and put it in a USB enclosure.
If the USB ports or anything other than the drive fail, the data is easily recoverable.
Given your use case, buying an external drive is probably fine, just don't get one from SanDisk.
Recent controversy over an absurdly high failure rate.
https://www.theverge.com/22291828/sandisk-extreme-pro-portable-my-passport-failure-continued
Might be fixed now, but i wouldn't gamble.