IMHO, using 10w30 engine oil in a shared common sump as you say some MF users do is a bad idea. 10w30 engine oil is not rated for gear use.
Your common hyds and gear rear sump in your 3000 should use a utf fluid. You can get cold weather utf or even synthetic UTF from many suppliers.
you can also put a mag block heater or 2 on her to help speed things up.
if parked in a shed or garage ( even better ), then even an old trouble lamp with a 120w bulb burnig under the sump can help.
couple all that with a battery trickle charger, a coolant lower hose heater, and an oil pan block heater and she will be much easier to start and bring up to temps and use in arctic weather.