I'd been a bit concerned it might cause example linking problems for the "other" んで, but they're all for ので.

Here's some examples in the wild I found by googling "xの、んで" and "だって。んで": 
https://twishort.com/cxGdc
"ベクは課長になって仕事が少し楽になったの、んである日社長に呼ばれていきなり襲われたの。"
"... って言ってにょるは社長にベクとの写真見せるの、んで社長怯むの"
http://icetea.blog3.fc2.com/blog-entry-5164.html
"それぞれがどう関わって、どう思いを重ねていくのか見たくなったの。んで、風、月がどうなるのかもとっても興味がわいてきたのさ。"
https://mastodon.to/@nashisugawa/139190
"「意見ともつかない個人的感情」だって？？んで、「それをわざわざ伝えるのが日本人」だって？？"
http://www.town.daigo.ibaraki.jp/sp/page/page000177.html
"あの娘と結婚したいんだって？。んでしたらいがっぺ。"

https://www.weblio.jp/content/んで
茨城弁大辞典

So I didn't put this in the already existing ので、んで entry because only んで is used in a sentence-initial position in casual 
conversation like this. It's basically the same as それで or ksb ほんで. I don't think it's just Ibaraki-ben but broadly used in Kanto 
(and probably outside it as well).
It's hard to find results for this on twitter/google etc. because you'll get so many hits for "学んで"　etc.