dissolve in cold water, ONLY THEN add hot water. The rationale behind it is that aromatics evaporate too quickly when the instant powder is infused with too/boiling hot water.
I use instant coffee for baking. And I had instant coffee as part of the tea-making facilities in British B&Bs (but I definitely prefer the tea there).
I'm thinking about making coffee ice cream and I was going to make a coffee reduction for that flavor (I experiment a lot. If it doesn't work I still have ice cream) but this sounds like a much better idea.
Espresso powder definitely has a better coffee flavor and I'd use that if allowed but instant still works well for quick work and light flavors. Always have some on hand for camping :)