chrome://flags/#enable-offline-mode
and
chrome://flags/#enable-offline-load-stale-cache
Unfortunately this doesn't work anymore - those flags were experimental.
In fact I've switched to Firefox (which is also much faster on Android) because Chrome tabs kept annoyingly reloading when the phone had no signal.
A piggy bank of commands, fixes, succinct reviews, some mini articles and technical opinions from a (mostly) Perl developer.