don't let "waiting for the new keyboard to arrive" be an excuse

I'm planning on not, either in the specific case or in general. (Which is why I went for my precommitment yesterday.)

(In case you're curious, my external keyboard is the one shown at http://www.dx.com/p/convenient-69-key-wireless-bluetooth-folding-keyboard-for-tablet-pc-smartphone-black-303707 ; fits in a pocket, allows full-speed touch-typing.)

available food/drink

I've already got my backpack ready for my first writing-focused trip to the library, come Tuesday: my preferred carbonated water and granola bars (which I should be able to have despite the usual no-food-or-drink policies of that library, as long as I'm reasonably discreet about it). If Soylent 1.4+ ever starts shipping to Canada, I might try that instead.

a comfortable chair

... Oddly enough, about a month ago I started thinking about replacing my current chair with a new one, maybe a recliner. This moves the idea up another notch or three on the priority list.

what is distracting you

At the moment, the main place I have at home where I can set up to write is my living room, in my Sheldon-like spot, where my roommate is usually working on their own projects, and/or listening to the radio and/or watching TV and/or trying to socialize with me and otherwise keep me from entering a flow state. It's infeasible for me to carve out a new workspace within the next few months, so as long as I can go somewhere where I don't have to worry about being talked at and around and with flickering images in my field of view, I should be able to manage. If I had better batteries for my laptop, a park bench would do; I might try that with my phone, just because I've now thought of it. Having excess books around is more of a help than a hindrance (which it should be, as even without the internet, I have several gigabytes of ebooks on my laptop at any given time).

whether the "distance and time to the library" is worth it

I go for miles-long walks daily. Won't be a problem aiming some portion of those walks to and from the library.

Regularly marking time out to do X will help it actually happen.

This has potential. Once I've found out if the library is the best spot, or I pick a different location, I can make it a regular thing.

raising the barrier to starting the internet

Maybe I can fiddle with the laptop's settings, so it doesn't automatically connect to the library's wifi.

so when you come back you can start with writing specifically

An addition - I can have my writing software automatically start when the laptop boots.