17 inch is bit heavy for my taste,of course battery is big problem cause of powerful hardware and when you add there wireless am pretty sure can't stay awake more than one hour...
I know you are on university so am not talking about next gen desktop PC what cost similar cash.Dell gives 3 years warranty which is great offer.
But still that is not worth to kill Toshiba what you own now,why not contact Toshiba service am pretty sure they can deal about that temperature problems,at least when they solve problems you can sell it.