Migrants to IJ, 2007

I remembered that I've seen the same error message (too big) when I first created some feeds.

I think it's because the very first update is very big (because all data from the last two weeks is updated at once) and takes some time (noted here). In one or two cases I had to wait at least a full week until the feed updated for the very first time. The "too big" message disappeared after that.

I could be wrong of course but I think you should try and wait some time and maybe the problem will solve itself.