Nintendo Switch: How often can you transfer memory data?

Since my switch is not working so properly and I still have warranty on Amazon, I want to send them back. In order not to lose my memory data, I thought that one could perhaps store the memory data first to the switch of a friend and from there to the new switch. The first step is possible in any case, only the second I'm unsure: Can transfer already transferred memory data or there's only "one chance"?

Of course, even if you buy everything 3 days a new one that works