Variable use question

I have a 848 byte binary buffer I need to get periodically from my Electron. I have been sending it using MQTT but I have yet to find a way to do MQTT TLS. (If someone can point me to a solution please do!)

To work around this I am thinking of using a Variable. However, there is a 622 character limit and it can only be a string.
I am thinking I can encode the buffer using Base64 and split it into to 2 variables. The base64 length should be about 1130 characters.

Does that sound reasonable?

Any other suggestions would be appreciated.