15″ Laptop vs 17″ Laptop

I’m in a position where i have to buy a new laptop for college and in the recent future for work.
I need a laptop for programming and adobe programs like photoshop, illustrator, premier etc…

I’m in between 2 laptops, MSI 17.3″ GP72MVR 7RFX and the MSI 15.6″ GP62M 7REX.
I would like the 17-inch one for multitasking (to be able to have multiple windows on screen) but I don’t know if it’s gonna be a big difference in portability. The 15-inch is 383 x 260 x 22~29 mm and weighs 2.2 kg, the 17-inch is 419 x 287 x 29~32 mm and weighs 2.7kg.

Is that a big difference?
Anyone got some suggestions or advise?