Anything with 600+ pages is fair game, although I generally only included the first book of a series if it qualified (exceptions were made for certain compendiums and borderline stand-alones). I myself am currently chugging through 'Three Kingdoms' during my time under shelter-in-place, which has probably helped my sense of stability a tad.
P.S. If you're going to order any of these during your stay in, do me a favor and go for the indie bookstores. It took a pandemic for Amazon to (maybe) give (some of) their workers paid time off, so go support something that actually cares.