It gets easier with time, I don’t find it any harder leaving with 4 than I did with 1 or 2 (just more runs to the car with all the coats, hoodies etc!) Practice makes perfect!
My top tip for leaving the house is to always have your bag ready. So mine is always packed with everything we need, so I can leave and just grab it. I imagine a lot of people do that anyway, but I remember being really surprised hearing a friend totally unpacked hers every day! I keep spare clothes, nappies, wipes, purse, snacks, tissues, plasters, a mask, spare change all in there all the time. So I only need to add more snacks and drinks if we will be out a while.