Tom,
6 inches put down in the fall should be composted to a couple inches by now and if your soil dries out rather fast what leaves remain will help keep soil moist. I'd go by feel. I mean reach down under the leaves now and in late spring and see what's going on with your garlic. If wet and shoots look bad, remove leaves, if not leave in place.

I always mulch mine with grass clippings as soon as I start cutting grass.

Here are a couple pics taken today. Notice that the mulch has been reduced.

I have not purchased garlic or scallions for over five years.
I grow enough to eat and replant my garden. All my produce is grown in raised beds or containers.

I leave the 2 inch layer of mulch over my garlic as it needs a continuous supply of moisture. Just make sure the soil is well drained to prevent rot.

Hope this helps.

update
 

[LEFT][FONT=Verdana][FONT=Courier New][SIZE=3][COLOR=#0000ff]well it's a good thing i asked and followed advice to remove the 5" of compressed, wet, heavy layer of leaves.[/COLOR][/SIZE][/FONT][/FONT][/LEFT]

[LEFT][FONT=Courier New][SIZE=3][COLOR=#0000ff]i went out last night and of the nearly 200 cloves planted only 5-10 were coming up thru the leaves. much of the leaf mulch was shredded but not that small and some of it was large pieces of leaves. the end result was that some of the garlic was growing just sideways! i have 4-6" greens that were trapped under the heavy layer of wet compacted leaves. so i pulled most of it off leaving an inch or so to conserve moisture and hopefully suppress weeds. [/COLOR][/SIZE][/FONT][/LEFT]

[LEFT][FONT=Courier New][SIZE=3][COLOR=#0000ff]i was thrilled to see that i have 99-100% growth in the bed. i was worried because back in december, before i mulched, none of the music had broke ground while about 50% of the other varieties had and were 3-5" tall, all this on dec 5th and the ground had not froze yet! since 70% of the bed is music it would have been a disaster if none of the music came up. most of the garlic is about 2" tall and straight, only the longer shoots were flat on the ground.[/COLOR][/SIZE][/FONT][/LEFT]

[LEFT][FONT=Courier New][SIZE=3][COLOR=#0000ff]6-7" of shredded leaves is a good insulation once the ground freezes to protect the garlic from thaws but i also think that by late march in my area i need to pull most of it off.[/COLOR][/SIZE][/FONT][/LEFT]

[LEFT][FONT=Courier New][SIZE=3][COLOR=#0000ff]tom [/COLOR][/SIZE][/FONT][/LEFT]