The Smallest Minority on earth is the individual. Those who deny individual rights cannot claim to be defenders of minorities. - Ayn Rand
You should just use a word processor of some type. Most have auto-save and grammar check, so would be a boon right there. (Having never used blogger, I don't know if they have such features. Firefox may have an extension, but who the hell knows if it will work correctly after an update.)
Blogger has a WYSIWYG function that is very useful for checking your HTML coding. It also has an auto-save function that is apparently not that reliable.
I've written posts in Wordpad before, but when I do that, if I've failed to close a tag somewhere it can be a PITA to fix after I transfer it to Blogger.
It's 98.6% file compatible to M$
It's not nearly as HTML hostile as M$.
I always use a text editor to write long posts to minimize the chances of losing all that work. At least for the body text.