Hi
@GaryBowler
I too am a Manhattan resident and have kind of agonized over this charging issue since June 2012 when I purchased a Chevy Volt and tried my hardest to drive on electrons rather than gas. I will tell you it has become MUCH MUCH easier since then to be All-EV in Manhattan over the course of the past 6 years. Particularly a Tesla b/c of the Destination Charger program.
Most importantly let me point you to the "urban" SCer in Williamsburg at the William Vale hotel. Technically it is not free -- Teslas pay $5 for an hour of parking -- but IMNSHO it is the Best Value SCer in the NYC metro area. I live Columbus Circle so Williamsburg is not too far away from me and b/c the SCer is in a lively neighborhood you can get a bite to eat or even a cocktail while your car replenishes electrons.
technically JFK SCer is the closest and
freeest of the NYC metro area SCers -- what with Peramus and the rest requiring a hefty toll to return to Manhattan. but the trek to and from JFK can be soul crushing so this is not really viable for people living in Manhattan.
I would also urge you to look at the Destination Charger map. There are Destination Chargers everywhere. I count 6 within a 3 block radius of my building and 10 within a 6 block radius of my building. but again -- depending on where you are located in the city, YMMV.
finally, you should look into a service like DropCar.com which is what I use in lieu of a monthly spot at a garage. I wholeheartedly recommend them.
Their "storage" rate -- which would suit someone like you who only drives on weekends -- is currently at $379/month (up from $320 a few months ago) and includes 12 ins and outs each month. They have a few garages in and around the outer boroughs but for the past month or so all the Teslas were being parked at the N 7th Street garage in Williamsburg -- a few blocks from the William Vale where the SCer is. The N 7th Street Garage has 2 Destination Chargers and a smaller Clipper Creek J1772 EVSE and DropCar offers free charging for Teslas and a whole bunch of other (paid) services, like car washes (and Oil Changes for ICE cars.)
Depending on availability of Valets they can pick up your car in as little as 15 minutes lead time, but it can sometimes take up to an hour, so it is always better to schedule it in advance. Return from Williamsburg to most parts of manhattan takes 45 minutes or less and again is better to schedule in advance. They have an App that works really well and they have $5 Million in liability insurance and will pay for any damage done to the vehicle while it is in their custody. (I can attest to this form personal experience unfortunately.)
They also have a "commuter rate" for $500/month that includes 20 ins and outs a month. which is what I generally use unless I am travelling for a few weeks in which case I will drop to the "storage" rate. It has allowed me to replace 2 garages in Manhattan for (really less than) the price of one. The going rate for a monthly spot in my neighborhood is $700/month but again depending on where you live, YMMV. While the DropCar service is not perfect, it works very well and i consider it a godsend.