A customer here has the identical problem. Horizontal scrolling and column width detection should solve the problem here. See attachment. Admittedly, the data is not readable after loading the drillthrough, but only when you have to click around a lot.
I would limit the AUTO-size of columns to have a proper width so you can read the header, because in case of text fields, you run the risk of having a lot of text and then the column would be very wide.
In general, it's important to adjust the column width easily, especially the last column which is somehow very difficult (not to say impossible) to widen.
A customer here has the identical problem. Horizontal scrolling and column width detection should solve the problem here. See attachment. Admittedly, the data is not readable after loading the drillthrough, but only when you have to click around a lot.