I would be speculating as wildly as you are.
Nope, pretty sure I had five meetings last week all with people in Scotland, who said they weren't giving at the moment and wouldn't be in the foreseeable future. The meetings I have soon in England, hmmmm I am expecting pretty much the same thing. As are others I have spoken to.
It's such a fluid sector it's impossible to lay down facts at this stage, I've no idea how a lot of it will pan out. However you must be aware that there are many, many charities operating in Scotland without the rUK already?
What's such a fluid sector? The voluntary sector is one of the most stable in the country.
Of course there are thousands of charities operating in Scotland. Who equally are struggling to raise money and will continue to do so in the face of economic uncertainty. Which will have an impact on the services they run. Which has an impact on their service user, mainly people who are in need of them most. Exactly the audience you profess you will save through independence. Well done.