I myself run a startup and recently started tying up with big co-working companies and online educational providers in India.

So yes, I don't think you should feel anyway less or intimidated by the brands you try to reach out. Based on the patterns I had observed in my conversions -
a. Email to right person is the best way or second best use of LinkedIn inmail
b. Use of introductions

And the most important - you should be able to really articulate well on how they benefit with your partnership.