In addition to bulk downloading report cards, there’s now an option to “Print (In Order)”. This will produce a single PDF with all the selected report cards linked together in the order you specify on the screen:

Select a collection of report cards or click the down arrow in the top left header box of the report cards column to select "All". From there, click the down arrow again and chose "Print (In Order)".
Please feel free to try this out and let us know if you have any questions or concerns. Thanks!
NOTE: Currently the Print (in order) action supports up to 50 selections per action.