SharePoint 2010 migration of huge Content DB Size

SharePoint 2010 Portal has one Content Database and the size of the  DB is almost 700 GB. The total number of Site Collections are 360 and only one content database is used for these site collections and it is growing. Now SharePoint 2010 has to be migrated. Is it possible to Split the site collections to different content db while migrating so that content db size can be controlled using database attach method ?