When my DS1 was 12-14mo he moved to one nap and had the morning, after nap and BT BFs. Then he dropped the nap time feed and just did morning and BT until 24mo when he dropped the morning feed. At 26mo he weaned completely with a little gentle encouragement from me.
DS2 was still on 2 naps from 12-15mo so had two daytime feeds in addition to the morning WU and BT BF. Actually he was often having a NF at 5/5.30am and then skipping the morning WU feed. At 15mo he dropped to one nap and I weaned the EW BF so we just had the morning WU, before nap (he always preferred this to waiting until after the nap from about 6mo, sometimes he fell asleep, sometimes not) and BT feed from 15-23mo (about then anyway). Then he had the morning and BT feeds from 23-25mo when he dropped the morning BF. He weaned completely by 26.5mo.
If I was away for any feeds or we were out and he didn't ask I didn't offer any particular milk replacement although DS2 did drink some cows milk in a cup if he asked (to be like his big bro I think) normally with a solid meal.
Once they are 12 mo+ they don't need formula as they can get all their nutrition from solid food. Breastmilk does contribute to nutrition after 1yo but is most important from the immunity point of view. Cows milk is just a drink rather than a food like breast or formula milks. The WHO recommends BFing until "2yo and beyond" as long as mum and baby wish to.
