You may have a problem if they have formed bulbs already but aren't full size. I'd leave them in the ground if they aren't large enough to harvest (at least the garlic and shallots) and would go to waste anyway.
How the garlic will grow in spring might give you some interesting results, as each newly-formed garlic clove may try to make a head and they are all scrunched up together in the space for one head. If your soil is very loose, you might be okay.
I cannot help with the onions as I never grow them (except for a few spring onions). The shallots and garlic chould be mulched over winter in your zone... just be sure to remove it when it warms up next year.
Yes the soil there is very loose. This was a new bed just made this summer using goat manure. I planted the garlic around the perimeter of the bed (mostly flowers) as a deterrent to rabbits. It's suppose to discourage them :-) but we also expected to eat the garlic when it was ready!
The shallots and onions are in the same bed but a different area. Plenty of room all around them to grow into. I will mulch them as soon as the ground has frozen so rodents don't dine off them all winter!