Generally, most of the single effect downloads are around 200M if you have to estimate.
Yes, some are larger...some are not ;-)
In re: Holed Up, after checking the video properties of my d/l, the file size is 448M (one of the larger ones for a single effect).
I would expect King of Warped to be in this size range also.
Sorry, I don't have that one specifically.
Now, fyi, if you are planning to order a Penguin Live event, those files can get much larger...over 1.5G in some cases.
Simply, they're longer vids...
As to putting that info in the product listing somewhere, you'll have to send PM an email with that suggestion.
Or, you could upgrade that 'primitive internet connection' to where it doesn't matter...Teasing ;-)
Best wishes!