What is the meaning/usage of に in the following sentence?


> ある事柄について感じた事(が、発表できる程度 **に** まとまったもの)。

So, I understand the first sentence, but I'm a little confused about the
second one.

My translation is: to have a feeling about a certain matter to the extent of
being able to declare about it.




Isn't this an excerpt of a dictionary definition, like what [this blog
cites](http://blog.livedoor.jp/bokuryu/archives/10319966.html)?

> 「感想」…ある事柄について感じた事（が、発表出来る程度にまとまったもの）。

In this case, it means:

> what one thinks/feels about a certain matter (which has taken shape enough
> to be expressed/presented/published)

As you have correctly translated, 程度 means "(to) the extent/degree", or you
could take Vできる程度 altogether as "enough to V". Anyway, both ～程度 and ～程度に
stands for the adverbial phrase "to the degree", but the form with に is
preferred when describing the state how the result is, while without に the
manner how the action is done.

> 30cm程度切る _cut (off) 30cm_  
>  30cm程度に切る _cut into 30cm pieces_ or _trim into 30cm long_

