She is thinking that she is a lame duck MP - disliked by her own leadership after the House of Commons "posh boys" comments, disliked by many voters within her own constituency for expenses irregularities and persistent lying, disliked by many just because she is such a numpty.
I am pretty sure that, should the boundaries changes ever get through, her specific constituency would disappear, so maybe thats in the back of her mind also.
She has said that the main reason for going is to publicize her "20 weeks" abortion upper time limit campaign.
I think she is a relentless self-publicist. A serial lyer. Someone with religious ideologies that lead her to ignore or reject the science.
She is doing her constituents a disservice, being effectively unavailable for a month. She is doing her party a disservice, she will be unable to vote, which may have some importance. And given that the esteem of MPs is at an all time low, she is doing the reputation of MPs a disservice by appearing on a programme populated by z-list celebrities desperate to reboot their flagging careers.
I find nothing admirable or likeable in Dorries at all, and all this does is to further my already low opinion of her.