According to http://www.gdal.org/drv_mssqlspatial.html I should be able to add a SCHEMA to my connection string to override the default "dbo" schema:
SCHEMA: Set name of schema for new table. If this parameter is not supported the default schema "dbo" is used.
But it does not seem to have any effect and I cannot find an example of how it should be done:
call ogr2ogr -overwrite -skipfailures -f MSSQLSpatial "MSSQL:server=myserver;database=mydb;trusted_connection=yes;SCHEMA=geoserver;" "C:\temp\MapVegas860\Buildings.shp"
How to import the shapefile into a 'geoserver' schema?