Camera upgrade, occasional weddings

Hey everyone! I want to take photography more seriously this year. I currently own a sony RX1R2.

I would like something quite portable, as I do a lot of adventures where something light and small is a big benefit.

For that reason I am really interested in the A7CR. It also fits my budget as I can find a used one for around 2500$ cad on facebook marketplace.

I have also been asked to do a be the photograph for a friends wedding. I am thinking if everything goes well and I have fun, I could see myself doing a business out of it and trying to find real professional contracts.

Since the A7CR does not have two cards slots, I would probably bring my laptop along at the wedding and do a backup midday.

Does that sounds like a good plan ? Or should I just invest in a bigger camera like the a7R5?

Thank you so much for your inputs !