If your graphics card is not top-notch (might be the case with your laptop), some programming technique on the campaign screen appears to run very slowly, and the larger map of EB naturally makes it worse. My (stationary) computer ran it slowly until I upgraded. Have you tried to disable character name and settlement display? On the campaign map, press Ctrl-T and Ctrl-N to toggle them. It made a difference to me back then. Also, make sure that you have the latest video drivers, as said earlier.