is it likely to be march time like usal or will they stick with the october

Currently, October 2015.

It'll have to be after the general election as LS is a Labour member of the House of Lords

and Baroness Brady is a Conservative member of the same body

the previous series to the last was a summer series, so maybe the same this year?

It almost certainly won't be, because of the election. And anyway, it hasn't been filmed yet. In the past, whenever there has been a spring/summer series it has been filmed by this point.