Data migration to Cypher Learning platform-Need 100,000 records to be imported at a time for historical data

Data migration to Cypher Learning platform-Need 100,000 records to be imported at a time for historical data

Hi- We are planning to migrate all the historical data from our current LMS to the new Cypher Learning platform and need 100,000 records to be bulk uploaded with a single .csv file. 
Currently the Cypher Learning platform has limitations of uploading only up to 1000 records in the sandbox. We need to have the limit exceeded more than 1000 because our data in one file is associated with 60K - 70K records. 

Need this to be addressed at the EARLIEST as we are soon approaching our BUILD PHASE completion.

Please advise.

Thanks,
Keerthi