It makes no difference what you do the IR and CPL on at the end of the day, at least in the eyes of the employer.
The da40 is not efis (i assume its not) so you will still get time on 'steam' instruments as part of your cpl. Why make your life more difficult during the IR by flying something with dials, when you could fly with the G1000? I completed my IR on the DA42, and then moved straight back to 'steam' dials for my first 'real' job. Without doubt the G1000 will help you during the IR, for situational awareness and many other things.
It did not prove an issue moving back to dials, and really if it does you should not be working as a pilot. Flying instruments is much the same, although the 'scan' works a little different for glass.
I work on both types from time to time, and although i prefer working with EFIS, it is always good to go back to dials and it does improve your scan skills.
As for time scales of completing and the weather, get used to it running late. Remember that in aviation people always advertise the minimum required, like time and money. Add 20% to cost, and 30% to training times- that is more realistic!
If you have your atpl subjects completed, then you will know all about how the weather can be in the winter - especially in the UK! Variable at best - but remember it will provide good experience of different weather conditions, including icing!
best of luck.....