Yes a decent quality extension cord with thicker conductors will help. The longer the cable, and the more power you expect to draw, the more it matters and because the voltage output from the MG4's V2L is already low, reducing any further voltage drop between the car and the loads matters more.
Just think about what exactly you want to run during a grid outage and how they are going to be connected. Can you access the plug for the fridge for instance?
You need to work within a power budget (and to an extent an energy budget).
Usually it's the fridge, some lamps, communications (internet router), chargers for phones/tablets/laptop, perhaps the TV if some important sporting event is on. A fan if it's a hot day.
Old fridges might be an issue to be careful of but modern units are usually pretty good and don't have quite the same surge power draw when their compressor kicks on.
All that can mean quite a few extension cords spread around depending on the home layout. So have a bit of a plan - one strategy is to consolidate activity into one area of the house. Minimise cable runs.
Plug in heaters generally are a no go as the power draw is too high, but a low power long-infrared heater can work. I have one with 300, 500 & 800 W settings and it works well as a personal heater.
Same restriction applies to washing machines, microwave ovens, electric kettles, and pretty much anything involved in generating heat (e.g. clothes or hair dryers). While you could boil a kettle using the V2L, you would not do that in a scenario where other appliances are being powered at the same time.
For a longer outage you may want to be able to cook something or at least boil some water. If the home does not use gas hobs, then I suggest a $25 portable butane camp stove from Bunnings or similar. They are actually pretty good and is exactly what we used in the early days of our backup set up so the wife could have her cup of tea. We have a 4-pack of spare butane canisters and they last for many years.
We also have a couple of battery camp lanterns and spare batteries as further backup, plus handy if you need to have light outside at night.
Other considerations:
- if the car is exposed to the elements (outages often happen in inclement weather), how well is the V2L adapter shielded from water ingress?
- trip hazard potential of the cable(s)
- how the cable feeds into the house and if that causes any issues, e.g. leaving a window or door ajar to run the cable through. For us it would mostly be insects/mozzies we want to keep out but for others it might be keeping the warmth inside and not letting cold drafts through.
