My younger bro, a FReeper as well, built me a custom laptop - used a Dell Inspiron as the base, and upgraded the bejeezus out of it. It stood up to temps in the Mojave, last month.
The apps we use, though, are graphic heavy, and 64MB of video memory is the problem - I'm asking the CPU to drink from a firehose.
Yow! 64megs! Must be awesome.