An iced latte is espresso, cold milk and ice — and it is the drink most often ruined by melt.
The order
Ice first, then cold milk, then espresso poured over.
Pouring hot espresso onto bare ice melts a great deal of it immediately. Pouring it onto cold milk that is already chilling the glass melts much less.
Pull shorter
The drink is going to be diluted by melting ice regardless. A ristretto or a normale rather than a lungo compensates.
Many cafés pull a double ristretto for iced drinks specifically.
Do not texture the milk
Cold milk poured straight is correct. Foaming it and then chilling gives you a collapsing head and a strange texture.
Big ice
A few large cubes melt far more slowly than a lot of small ones, for the same cooling. If you make iced coffee regularly, large-format ice trays are the cheapest improvement available.
The alternative
For a genuinely undiluted cold drink, cold brew concentrate over ice, or a shakerato.