Can I have 2500 repositories in single project ?

[Silambarasan]

In our team , we have 2500 projects to migrate to bitbucket from SVN. We plan to group similar repositories into one project. By that we can create 10 different projects and each might have 250 repositories. Though we have common repositories in different project. 

1) As far as my understanding, multiple project required only for limiting developers permissions for the project they work on. In my case, my developers, might need to access any repositories. So in my case, multiple projects are not required i believe. Is there any other rationale to grouping repo in multiple projects ?

2) We plan to create build pipeline/CI pipeline for project1 which intern required to clone the repo in other project as a dependency. Can we able to clone other project repository ?