Solid advice, I was planning that for my next campaign. Not doing exactly the DMG variant of day/week for short/long, instead taking inspiration from Adventures in Middle Earth (Tolkien 5e). Short rests are overnight. Long rests are overnight in safety and comfort. So if on your journey you get to a sanctuary like Elrond's, you get a long rest.
My favorite solution for this issue is not for everyone. 13th Age, a d20 game that came out before 5e, has at-will, encounter, and long-heal-up as their recovery options for features and spells. (Yes, some spells are encounter or at-will.)
A long heal up happens after four encounters. Could be a three week jungle trek, could be a morning (mourning?) of dungeon crawling. DM can give it sooner if the encounters are particularly hard. Players can take it early at the cost of a campaign setback. (A currency they use in a few other places, like a guaranteed successful retreat.) A campaign setback is just that. Maybe the cultists completed another stage of their ritual, or another caravan was taken by bandits, or the werewolves infected another rancher. Whatever makes sense for delaying.