Scaling, and grid problem in cadence

I made a gds file with 5 mm*5 mm size in Cadence virtuoso. The manufacturer company told me that they shrink the gds file by 90 percent for mask fabrication, and if I want my chip size to not change, I must enlarge my gds file by a factor of 1.1. I only have to scale the via sizes back to 100 percent.

I used Xstream in and using scalefactor in the options I enlarged my gds by 1.1 factor. The problem is that since my grid size was 5 nm, and by the scale factor it changed to 5.5 nm, I need to change my grid size to 0.5 nm. Otherwise some lines will be open and I will get DRC errors. 

My question is, how can I change the layout viewer grid, so it can recognize 0.5 nm as well, so I can scale without adding any issues.

I am using Cadnce virtuoso version IC6.17

Thank you
Regards,
Moeid