As one of its daily deals, Amazon offers the SwissGear Laptop Backpack in Red/Black for $36.99 with free shipping. That's $23 off and the lowest total price we could find. It measures approximately 14x8x19" and features a padded laptop pocket and padded tablet pocket. Deal ends today.
Orders placed via 2-day shipping will arrive in time for Christmas. (This option is free for Prime members, but an extra $13.07 for everyone else.)