You can always experiment with some tubers that you think will be excess, but don't rely on that method totally. My thinking is that the tubers will dry out and die. I have found that they are not like cannas at all, which will survive if you treat them as you suggest.

Dahlias are a lot of work, but they are so beautiful that, to me, they are worthy of the extra effort needed.

There are several postings about how to overwinter the tubers.

Here is a link that might be useful: dahlias are in for the winter.