Yes, it's very simple to do a preorder through the store.

Set-up the store item like you normally would, but when you enter the Product Options, input '9999' (or a really high number that you'll remember).

You can create a "Pre-Order Coupon" if desired. Under 'Admins'>'Billing'>'Coupons', you can manage your coupons and add an expiration date if desired. You can also set the coupon for a one-time use.

When the pre-order is finished, you can return to this product in the store and do some math on how many sizes were ordered

-OR-

You can head to 'Reports-Billing' and sort the sheet by 'Products' and set the date range you'd like to collect. You can filter the page by the name of the Store item. It'll show you how many shirts were ordered.

'Details' tab will show you who purchased AND what size was ordered.

Download the file to .csv or Excel so you can sort and Sum the sizes individually for easier tracking.