The mileage estimates are based on your current MPG, not an average. There are about 6 different test cycles. A lot of people get on a highway and run at a fixed speed and then report their results. They can vary widely. Car & Driver has reported that EVs lose about 41% range in cold weather driving and 19% in hot weather driving. They are also based on using DC fast charge up to 100% to get those range estimates. One EV site says that VW's battery warranty is the same as Tesla's 8 years or 100,000 miles. But another site says this is to about 77% capacity. I'm not going to drive in such a way that the battery loses that much capacity.When the weather here in the Chicago area was around 60-75, and I wasn't running either the heat or the A/C, I was routinely showing 295 to 305 miles at the beginning of a full charge. I don't drive like a granny or anything. I just drive like I have the mother in law as a passenger, and even then I sometimes open it up just to feel the power.
Just as with ICE vehicles a BAD driver can waste up to 25% of range. I've never gotten as little mileage as the EPA rating suggests. I really don't have enough information on the ID.4 to know all that I wish to know.
I don't believe that the ID.4 has a heat pump. Tesla 3s sold in the USA (I believe) do not either. But Canadian models do.
I do not like the assumption that a 10% reserve is adequate. That is only 28 miles (at best). I want to be warned at 50 miles range, especially due to the lack of chargers where I live. I wonder if a person could buy a Canadian model and if it would have a heat pump.