I live within 3 miles of a branch of all of the major supermarkets in the UK except Waitrose.
The only time I can possibly go shopping is after 7pm and even if I go in with a list of stuff and stick to it the round trip is 2 hours because of the checkout queues, car park queues and crowded shops.
I don't know if you have ever been to a supermarket after 7pm but good luck finding any fresh fruit and veg that hasn't been squashed to a pulp.
The only reliable shop near me is a particularly well stocked Morrisons Express but it's cheaper and easier to shop from Ocado.
I have that exact coat and can tell you that it really isn't particularly warm. Even with three layers below it isn't good below about -5c and is particularly bad in the wind.