Explore Query: It would be nice to combine Advanced Date Range selection with the option to check for NULL

I want to report on tickets which were open at the end of the previous month. Using the backlog dataset is not possible because I require ticket attributes not available in the backlog dataset.

So I thought it would be as simple as including tickets filtered where

ticket create date is 
from [all history]
to 1 month in the past (eg 31/5/2021 when today is 22 June 2021)

and

ticket solved date is
from 0 months in the future (eg 1/6/2021 when today is 22 June 2021)
to [all history]
or is NULL

But here is no way to do that without creating a custom attribute which seems to be a huge overhead.