2011 X5 35d winter questions

[N52SK]

Hey fellas,

I've got some specific questions that I'd like answered and could not really find searching and asking around. Were considering a 2011 X5 35d with the full load - sport pack, hitch, premium, technology etc. We live in a Canadian climate but garaged most evenings.

1. Wife is a home care nurse so she travels the city giving meds etc. Its about a 15 minute commute to work then 5 minute mini commutes within the community. She will put on over 100km each shift in city conditions and she plans to turn the vehicle off during visits - so 5 minutes of driving followed by 15 minutes of being parked and off. Of course this isn't ideal but but would there be any long term negative effects owning a diesel given this circumstance?

2. Warm up time. Is it noticeably longer warm up time than a gasoline engine? Is my wife always going to be cold when she is working because the engine wont get up to temp and then maintain the temp? If we get the comfort access package i was thinking she could lock the door and let it idle in winter.

3. The odd weekend we are way up north, -30 degree temps and sitting outdoors. Anything to be aware of? Idle the vehicle 1x day for an hr? Should I get an oil pan heater, hard wire in an intelligent charger?

4. Our current E70 3.0 gets about 12L to 13L per 100 blended city/hwy. How much better can we expect? Premium gasoline runs about $0.15/L higher than diesel where Im from. Im wondering if there will be any savings even after higher maintenance costs.