I have an older Deuter backpack that would probably fit that laptop, it's got a builtin
camelbak pouch and a pullout high-viz vest. I was as happy with it as any backpack,
but being in the sweaty straps for a couple of hours a day caused my skin to break out.
So I got panniers that I use instead, and now both my skin and my spine are happy.

(Does it have to be a backpack? If so... wanna buy a used one :-) )