I have mine set to 'auto loot' as well, but I did that long before the Winter event. Also, I have found the snowman attack to be far more rewarding than digging snowballs.

I have 5 alts, all lvl 50. I just ran enough snowman attacks and snowball digging until I got enough for one of the snowball guns. Once I had one, I only do the snowman attacks on that 1 character, I haven't dug since and I have a load of winter kit.

My proceedure is to log in with that 1 character and depending on the time, (whether its close to one of the 1/2 hourly attacks) I will either wait for the attack or run the Ice race for my Q Autographs.
If there is time, I will switch characters and run the Ice race. I will then switch back to do that snowman attack. you can often clear a zone, then switch instances to help finish off other zones. This will net you more winter goodies. Once thats done, I'll switch to my next character to run the Ice race.

After 2 or 3 snowman attacks I'm usually done for the day.

Stockpile everything in your account bank to share between characters.
I have several coats on all my characters, some have nanopulse weapons and they all have 520 Q pictures