An RTE spokesperson said that the staggering ratings were based on the veteran broadcaster's extreme "popularity" among Irish viewers.
"The strong viewership the two programmes attracted can be attributed to a public appetite for an Irish perspective on American politics, and indeed Charlie's own popularity among the viewers at home," the spokesperson said.
Charlie's continuous whining about his extreme loneliness continues in the same cringeworthy vein as the first show.
On Monday night, over half a million people watched as the reporter used his documentary to announce that he would be leaving his job as US correspondent.
"It's meant to be a four-year posting but there's absolutely no way I'm going to stick it here for four years. I just couldn't do it," he said.
He added: "I'll be back in Dublin, I'll be walking around and I'll go back to doing the job I was doing before I left."
A source said: "He spoke with management over Christmas and it was decided that he will be coming back this year."
The Washington role is one of the most coveted in the business and has traditionally been occupied by up-and-coming reporters such as Mark Little. The documentary has been widely criticised for Bird's downbeat assessment of his job and last night it continued as he talked about his loneliness and feeling disconnected from the RTE newsroom.