You will be fine. You can even do duffle bags. The personal item sizes are fairly generous, it's 18X14X8 and easily accommodate rolling under seater, backpacks etc. We recently did family of 4 with 2 kids with 2 under seaters and 2 duffle bag. One of them was way too large but no one cared, however that's YMMV situation. Soft bags can be squished into the personal item space.