Note: this applies to ALL cars, not just the 1007.
The door freezing problem can be worse in the UK because our temperatures often range from just above freezing during the day (so snow/ice/condensation melts and water runs into the seals) to just below freezing at night (so the water freezes in the seals). High humidity can also allow water to run in and freeze onto the seals.
This cycle doesn't occur in colder countries, where the air may be well below freezing day and night. As the air is colder, it won't hold so much water so really cold climates do not appear to have the same condensation problem.
A very thin smear of silicone grease will help to stop ice sticking the rubber seals together in the winter. Take time over this, there are many small contact areas and don't forget the ones on the door, especially the big one at the bottom of the door which is easily missed.
Do not put too much on - wipe it off with your finger after applying or it will attract dust and dirt - or get on your clothes!
Note: Silicone - not silicon. Do wear gloves - although it won't harm you, this stuff is very sticky to get off afterwards.
Do not use ordinary grease or Vaseline as these are petroleum-based and may attack the synthetic rubber in the seals.
If you are in a secure area, you could try leaving the door partly (enough for a gap between the seals) open overnight - then you won't have a problem getting in in the morning!