Here's my advice based on previous experience.
Pack two bags.
An overnight bag, then a longer-stay bag. Leave the longer stay bag either in the car, or at home by the door so someone can get it for you if needed.
Bag one: With everything you need for labour and if you are in just 24 hours- maternity pads, paper pants good you can rip them off and bin-em. Most of it has been mentioned.
Bag Two: A long stay (post-labour) bag. If you need to stay in more than 24h, send someone home, or if you came by car, to the car boot for the second bag with extra clothes, extra baby clothes, extra nappies etc snacks, bf related things etc.
A word of warning about phone chargers- you're generally not allowed to plug anything in in a hospital unless it's been safety checked as it's potentially a fire hazard. Nightmare if your battery is low so I advise leave it on airplane mode or off as long as you can bear. It's your neck if you decide to plug something in sneakily but prepare to be bollocked.
Sweets list is sooo long! Some great ideas but doubt it's all necessary and some can go in the second bag.
Bear in mind most hospital wards are really warm so you probably won't need fluffy dressing gowns etc, a thin one will take up less space. Perhaps ask the midwife or someone you know who's been if it's warm on the wards. I suppose in wintr you'll need more.