Possibly not hopeful in relation to cold, but my brother left my car door open and it had to be jumped to start. By the time we stopped at mcdonalds about 7 blocks down the road (we got hungry waiting for the jumper guy), it was all set to start on its own. So less than 7 blocks on a regular day?

1) "Usually when a car is jump started, it is driven long enough to fully recharge the battery. The length of time to fully recharge the battery depends on the amount of discharge, the amount of surplus current that is diverted to the battery, how long the engine is run, engine speed, and ambient temperature. That is, an alternator is sized by the car manufacturer to carry the maximum accessory load and to maintain a battery and NOT to recharge a dead battery. For example, if 300 amps were consumed for two seconds to start a car from a fully charged battery, it will take an 80 amp charging system approximately nine seconds to replace the power used. If 25 amps are available to recharge the battery, it will take 12 minutes and 30 seconds at one amp. With a dead 120 minute RC battery, it would take approximately 45 minutes at 80 amps, 2.4 hours at 25 amps, or 60 hours at one amp to obtain a 90% State-of-Charge. If you have added lights, audio amplifiers, two-way radios or other high powered accessories to your vehicle and engage in stop-and-go driving, the alternator might not produce enough current to keep your battery fully charged. You might need to increase the capacity of the charging system. Ideally the combined load of all the accessories should be less than 75-80% of the charging system's maximum output, so that at least 20-25% is available to recharge the battery." Source: http://www.topbuzz.co.uk/info/car_battery/car_battery.htm 2) "How to Keep Your Battery Alive: A little maintenance will keep your battery charged through the cold months as well as the warmer ones." http://www.ehow.com/how_10758_keep-battery-alive.html 3) "If the battery won't start your car, you usually refer to it as "dead," even though that's not technically correct. A car battery that's merely discharged - from leaving your headlights on or from a damaged alternator -- can be recharged to its full capacity. But a battery that's at the end of its service life can't be recharged enough to restore it to a useful power level. Then it truly is dead, and must be replaced. If the battery is discharged but not dead you can jump-start it from another fully charged battery. About 30 minutes of driving should allow the alternator to charge the battery until you can get it to a service station for a full charge. However, if the alternator or another part of the electrical system in your car is damaged it won’t be possible to to recharge your battery. So if your battery keeps discharging, first have your electrical system checked. What looks like a bad battery could be an electrical system problem; if you have a bad component in the electrical system, it will keep draining a new battery, and you'll be stranded again and again." Source: http://www.batterycouncil.org/jump.html