Suggestion: What about configure gridColumns per Container?

[samsonovkirill]

Sometimes it's convenient to change gridColumns value on Container rather then per project globally, if it make sense I have a small solution of this problem based on the same idea with a gutter context but Provider is created on Container level and consumes gridColumn on Column level, if there is no gridColumn prop specified in Container the default value from config is applied.
Example:

<Container fluid style={{ lineHeight: '32px' }} gridColumns={13}>
  <Row debug>
    <Col lg={7} debug>1 of 2</Col>
    <Col lg={6} debug>2 of 2</Col>
  </Row>
</Container>

Row consumes value from nearest Container Provider. I've created a PR #113