EAD Renewal on an E3D - Timings and Logx?

[Richo]

My Wife's E3 Visa runs out in August 2017. We were thinking about doing a run to Canada or Barbados...but my Visa is an E3D (Dependant Spouse). To work in the US I need to have an Employment Authorisation Card (EAD) which I applied for the first week we arrived and is good until the end of the Visa (August 2017) but it took 150 days (5 months)...therefore am I right in saying that to ensure I can still work we will need to apply 6 months earlier than August 2017 to ensure my new EAD arrives before the previous one expires?

...and then again our E3 Visa's will need to be applied for every 18 months rather than 2 years going forward?

Anyone had any experience with renewing EAD's on an E3?

Thanks.