From someone else in a similar situation at that age: -
My Ds1 transitioned to one nap at 10 months, has always been on the lower end of sleep needs. At 18 months he started "not napping" about once a week. Now he's nearly 2, he skips his nap sometimes twice a week. He does stay in his cot for on hour though for quiet time and just plays and talks to himself. I do think the final transition to no nap is the longest one and they really do need to be offered it every day, you never know when they are extra tired or sick or teething. When DS1 naps, he will sleep for 3 hours if I let him so I have to wake him from the nap, otherwise he takes over an hour to fall asleep at night.
HTH