i use set timescale to 5. its perfect. it not as slow as real time so there is sime sense of time passing but its not ridiculously fast like the vanilla settings.
there's also an old .ini setting from Oblivion and Fallout 3 etc but im unsure how well/if it works
fGlobalTimeMultiplier=1.0000 - Raising the value above 1 speeds up the rate at which world time passes, lowering it below 1 slows down time. This setting is interesting for watching rapid-motion sunsets/sunrises for example.