Welcome to the forum spellcheck07. Due to TS4 being a close worlds only the lot you are actively playing is loaded. There are some interactions that you can direct your sims to 'do' while you are on another lot but they don't really work that well. Perhaps skilling up is the best interaction but when it comes to filling needs often it is a complete fail really! lol For, as you say, you'll travel home and all the sims needs will be only half filled. But this can also work to your advantage as often 'at home sims' who have their needs in the red can actually be ignored as they too will often half half filled needs when you arrive home. Especially if you choose 'look after self' as the away from home action.
I usually play with a full house on full autonomy and like
@Junan mentioned it is really all about timing. If I know I am taking out only a few or one of my sims then I'll top up the needs of the remaining sims before heading out. If there are kids that have homework to do then I'll take them with me, have them complete their homework and then send them home etc.
You can also temporarily bring an 'at home sim' to the current lot, take care of their needs and then send them back home again too. More times than not if I really am concentrating on just one sim I completely ignore the at home sims as I know they will more or less be ok by the time I arrive back to the home lot.