Hi Sarah, you can use the Filter Orders by Date filter to limit Orders to just those within that date period. regarding the fatal error issue you can use the Volume Offset and Limit Volume options under Export Options to generate a smaller export and run it sequentially to get all your Orders out.
I’ll be further optimising the Orders export filtering options in the 2.0+ updates. Regarding scheduled exports please open a Support ticket as I will send you an early release of the next Plugin update with an overhauled scheduled export engine (we now support multiple scheduled exports!). 🙂