It'll take them 6-12 months just to go through their legal, privacy, finance, etc processes. That's assuming they've decided to use you.
You should also expect to hire or contract a lawyer as they're going to want a custom contract rather than use your terms of service. There is a good chance they'll have their own contract but you can also have them modify yours. Expect several rounds of contract editing.
Getting stuff into a big company is a process. Source: I work at a big company and it's a pain in the ass to buy anything.
Honestly don't be surprised if you have a year of positive conversations and then it fizzles into nothing. Or don't be surprised if they're super excited but their legal or privacy teams shut down the deal.
Sales with big companies just takes time and can fall apart in many ways.
I also read that you may not exist in a year. Maybe it's worthwhile to consider an acquisition or acquihire by them?