No cold start issues in Raleigh in the 22 years that I've been driving diesel 123's (79 240D, 84 300D Turbo wagon, & 84 300D Turbo)- I've only used the block heater 2 times in the past - I just listen for the 'click' after the glow light goes off, then turn the key... fires right up.

Get a good quality battery & stay current on your valve adjustments -

As for B100, I've been hitting up buddies that own restaurants to secure their waste oil -

Bryan in Raleigh