Its just a matter of having enough redundancy. May get the adrenalin flowing a bit but if you keep your cool any well trained IR pilot should be able to get it back down.
1)
Blackout in IMC at night (worst case senario?) - not a problem since the advent of LED torches - they run for a long time. 1) I clip one onto my headset for night TOs - 2) have another in the side pocket. 3) Regulation shock-proof torch in the pocket between the front seats, 4) another in the flight bag. 5) If all else fails, I have a tiny LED torch on the aeroplane keys.
2)
Total comm loss in IMC - 1) pull out the ICOM handheld from the pocket behind the pilots seat. The charger is plugged into the rear seat cigarette lighter so is always charged. 2) fire up the mobile phone - ring the briefing office if you can't think of anyone else, they will sort it out (speaking from experience!). 4) Use sat phone as for 2. 3) Fire up the tablet computer and the Next G modem and send someone an email. 4) Start a new thread on Ppruine -
"Help! I have total loss of comms". Do you really need to talk to anyone anyhow?
3)
Vac pump failure in IMC - 1) Look at the stdby electric AH and blank out the U/S one. 2) Fly partial panel - worth practicing regardless of how much technology you have. 3) Use the electronic AH on the tablet computer (runs off solid-state whiz box). 4) Use the flight instrument screen on your Garmin portable GPS - 496 refreshes fast enough for this to be a viable option. Vertical card compass makes it easier to fly a course. GPS makes compass pretty redundant anyway. Biggest problem in the Bo is having to hand fly as the AP goes U/S.
4)
Total loss of navaids in IMC - 1) get yourself some radar vectors. 2) some panel GPS's have battery back-up. 3) Use the portable GPS on the yoke to track to a destination and fly a GPS arrival or RNAV appr. 4) Use USB GPS and geo-referenced appr plates on the tablet to get you home. 5) Pull the spare GPS outta the flight bag if needed. 6) Use the VOR feature on the Icom handheld.
5)
Total loss of engine power in IMC - Use moving map and terrain avoidance feature on any of your GPS's to steer to the best possible spot to pull off a successful forced landing.
6)
If all else fails - stick your head between your legs and kiss your arse goodbye!
My worst multiple failures were: 1) oil drained out of the mag compass; 2) AH rolled upside down; 3) total electrical failure! Fortunately happened in VMC on top and the destination was CAVOK. Private hired ****-box aeroplane. Owner got really upset when I wrote up the maintenance release!
Dr 
PS: Think these senarios through so you have some idea of what you are going to do - before it actually happens.