I drive this frequently (though not so much in the last year because covid), although from south of Cambridge, and it is long, but I've done it for so long it's just something I do (live south of Cambridge, family in Glasgow).
I used to do m6, but I find it a terrible road for traffic jams, I've never once done the m6 and not been stuck in traffic for hours.
Normally, I do a1, a66 m6, m74 and I always hear about m6 issues on the radio when I listen to the traffic.
It's about 380 ish miles, normally stop at Blyth or wetherby and then at a cafe along the a66 somewhere. Leave early, and in Glasgow mid-afternoon all being well. Last one, left just after 8, was in Glasgow just after 4.
I did it recently with the kids on my own and have done it before with the kids on my own. When dd was smaller, I thought about stopping overnight, but tbh when I did that it was more of a faff (there is a premier inn at blyth and a days inn at wetherby), and when I did that I left late afternoon, stopped and slept overnight and then carried on. I'm not sure it made my journey any easier - dd didn't sleep well because she was in a different bed and so we were both tired and cranky the next day.
Personally, I think the best bet is to plan to leave as early in the morning as you can, and do it in a day. But I know that if you don't drive that distance normally it can be tough going, especially if you don't share the driving.