DD self weaned at just over 2yo, and for the last couple of months she was only having one feed (at about 4am - she'd get herself out of bed, come into mine, help herself then go back to sleep for a couple of hours )
I did 2 feeds a day for about 18 months, (from 18 months till 3) then 1 a dy for 4 more months till self- weaned. A good few of the 2 feeds a day were one feed actually if I was out in the evening. So I am sure your supply will be fine, I think your body adjusts quite quickly.
I have seen people on here talk about how their toddler kept up the bedtime feed for x months/years. And I suspect my 10 month old would like a bedtime feed for a while, although it will be easy to give up day time feeds. But does this really work? Does the supply not drop away really quickly? I'm never sure if when people say their toddler was having bedtime bf, if they had supply kept going during the day / night by a younger sibling?