BCP would work, you may need to create the needed format file for it to load it.
What errors do you get as loading INT VARCHAR etc via BCP does work.
Alternatives are things like SSIS, SAP Data Services etc.
You may even want to play with changing the recovery model (assuming your in FULL), while the bulk load is happening, switch from FULL to BULK LOGGED then back to FULL, but you would need to look into the differences between that and if it falls into the agreed RPO/RTO's etc. That way it's in a minimal logging rather than a full logging mode for the duration of the BULK INSERT.