is there a way to change the size of a video being uploaded without getting this?

No. If you limit the size of uploads and try to upload a file larger than the limit you've set, you'll get an error.

so am I able to change the upload size and where if possible?

This is the media manager in the AdminCP for Pages, correct? If so you cannot change it, however the limit is removed in 4.5.

Quote

- Removed a hardcoded limit of 5MB for files uploaded to the media manager.