Assuming you have no car and are stuck wherever you go, why not just move to the South Bay, e.g. Mountain View.

It meets all your requirements, plus there's no scenery to stare at to even get the slightest bit distracted. AND, there's entrepreneurial activity going on 24/7 to keep you motivated.

As a side note, I had a couple friends go to Thailand with exactly this in mind, and honestly they didn't come back with much. Beaches can be distracting...

Panama. Panama. Panama. I moved here 5 years ago. 2MBps for $29/month. Much more affordable living than SF (where I used to live).

There's a lot of info out there -- where in Panama should I look? Most of the short-term rentals I see are vacation rentals, which can actually be pretty pricey. Any recommendations for where to look?

I suggest taking advantage of the opportunity to learn some Spanish while visiting, if that's consistent with your goals. http://spanishpanama.com/ has some deals where one can stay with a local family + they have a hostel option. There are some hostels that can provide a/c private rooms like Relic and Balboa Bay. However it might be possible to find something a bit more comfortable and spacious. If you have some Spanish language ability already, you might be able to post on encuentra24.com and find something there. I understand what you mean about there being pricey short-term rentals listed online though. Feel free to email me for further help (see my hn bio).

I had some good success running away to Tahoe. Good internet access can set you back, but I prefer to work locally.

If you can find a decent location with enough space, bring enough food to last for a week and you can blow steam up on the mountains, or rolling through fields of snow (whatever floats your boat).

Come to Cleveland! It's cheap, and no beaches or sun will guarantee that you'll be indoors coding all day :)