The lockup is not normal. It is normal that the CPU/GPU usage can spike close to 100% but that is usually only temporary, in areas with a lot of scripts being triggered, or in combat with explosions going off, etc. Heat issues can cause the GPU to be maxed, if it clocks itself down to avoid heat damage.
If you do not have a laptop cooler, try placing a book, or something, under each corner, so there is as much surfaced open as possible, while remaining stable, then point a fan at the laptop so there is airflow under the laptop and across the keyboard.
If it isn't heat related:
Try doing a clean boot and then test the game. Click Start, or hit WinKey-R, type in msconfig and hit enter; in the General tab, click Selective Startup, uncheck Load startup items (if required) and leave Load system services and Use original boot configuration options checked. Next, click on the Services tab, check the box to Hide all Microsoft services, then click the Disable All button (maybe make a note of which are currently enabled/disabled), then click OK and reboot the computer.
Run msconfig again to switch back to the normal boot configuration.
Try resetting your graphics driver's 3D settings to default (right click an open area of the desktop to start the nvidia Control Panel).
Make sure the Virtual Memory setting in Windows is set to automatic / system managed, rather than being disabled or set to a fixed size (to check or change virtual memory settings in Win 10,
see here), and you have enough free hard drive space. Unless you reboot before playing, memory usage can tend to increase during the day, and might account for performance dropping faster the longer the system has been on (though less likely to cause CPU/GPU usage spikes, at least directly; the way the game handles low memory might, theoretically).
Does disk activity increase beyond normal leading up to the freezing?
One person with performance issues with D:OS EE on an i7 CPU fixed it by setting the game not to use the first 2 CPU cores, since Windows was running everything else on them, as well. Another was getting stuttering, and fixed it by switching the game to use only one core, applying, then switching it back to all 4 cores.
To try this (though these issues were not related to the time the system was running), start the game, then start the Task Manager (Ctrl-Shift-Esc or right click an open area of the Task Bar), switch to the Processes tab, right click on EoCapp.exe and select 'Set Affinity...'. After that, try unselecting Core 0 and 1, apply and test the game, or unselect most of the cores, apply and select all of them again.
Also in the Task Manager Processes tab, try right clicking EoCApp.exe and under Set Priority, select High or Realtime.
Nvidia may have newer graphics drivers, with more up to date fixes that you could try. If you already are, Dell's drivers should be better optimised for that system, and be more stable, so you could try reverting to those. See
here or
here, for example, for guides on how to cleanly reinstall/update graphics drivers.
