I don´t see an issue with random encounters.
What we see is not an actual world. it is scaled down. the distances are scaled down.
I would not mind being randomly encountered by goblins at night, when resting near a goblin location. Or by giant spiders in the forest. Or by gnolls on the street.
BG1/2 both had camp encounters, kingmaker has it etc. Putting that in place is probably no problem and a little more believable than always teleporting back to base. Unless you have some kind of explanation for that like in BG2 ToB.
The only other option to not sleep-cheese is basicly to put timers on events. if you trigger XY you have only limited time to complete a quest. if you chose to long rest -> you lose time. Atm it cost you absolutely 0,0 to rest after every fight and full reset. Might aswell just full reset all abilities and health after every fight then, cause its no difference.
This would be possible but would certainly be even less DnD than this game already is.
