My reasoning is I may as well change the panel and house wiring while the electrician is there. It's a small house so really it would be more efficient to get it all done at once.
My other concern is the growing number of things using power. When the house was built TV, fridge, stove, washer, dryer, lights, furnace and water heater. Now there's Xbox consoles, big TVs, computers, cellphones charging, A/C units.
This is small town Canada too probably more expensive than the US unless I can get a good buddy electrician after hours deal.
I haven't gotten bids yet to know for myself, but assuming you feel confident enough to do the wiring after the new box install, it shouldn't be outlandish price-wise, even in CA.
I'm only doing that because I don't want to mess with the live feed from the street, though I did watch some electricians replace my mains breaker. Their solution was being very careful with rubber gloves and rubber-handled-pliers, but I just don't think that's for me :).
Why would you rewire the house to run a 240V plug for your car? That's nuts. You'd add a dedicated 240 circuit. You're probably still looking at a a minimum of $1k and likely in the $3-5K range, especially if your panel needs to be updated/expanded, but there's no reason you'd need to rewire your whole house for this. As for the outdoor outlet, there are exterior rated outlets (and presumably exterior rated chargers). Code isn't the concern.