As Scuttlebutter said, there are some people who keep their dogs outside, one of whom is me. As SB said, outside dogs still need really good quality shelter.
I have a slightly different take on it, in that we have 2 working farm dogs who live outside 8 months of the year and I actually have no problem with certain working dogs living outside . BUT and this is a HUGE BUT mine live in a properly constructed, heated, kennel (think small garden shed) with proper dog beds and double duvets and blankets decent bedding, with a secure, lockable run and they are full working sheep & cattle dogs who start work at 6am with my DH (who is a farmer) and are on the go with DH outside all day.
They then get shut in their kennel at about 9pm after getting fed in the kitchen, when they are only too glad to collapse in a heap. The reason they live outside is because they are covered in cow muck and mud most of the time. In the winter, they live in the kitchen because DH & I damn well wouldn't want to be living outside in the winter, and so we don't see why they should.
Quite apart from the fact my dogs live in the kitchen in winter, they also have their thick winter collie coats that grow in accordance with the seasons - coats that grow because they are outside 90% of the time and never bathed and they are a fairly hardy breed with double coats too. An "indoor"/short haired/fine coated dog without adequate insulation will really suffer if outside in the winter, regardless of a heated kennel. Not only that, but my dogs are used to being outside a lot - they have acclimatised to it.
It seems to me, that you need to really assess your priorities. Your DP is being unreasonable to expect indoor dogs not used to being outside, to suddenly live in the garden. Especially without good, well constructed and adequate shelter.