This government publication on the thermal performance of masonry chimneys and fireplaces didn’t find temperatures greater than 855°C and that was the gas temperature in the flu. This test of a rocket stove found a maximum average temperature of 945°C and a max temperature of 1049 °C. The third paper found that for small flames (less than about 1 m base diameter), continuous flame region temperatures of around 900°C should be expected. For large pools, the latter value can rise to 1100~1200°C.
So I think it is safe to say the 1000 °C would be considered a hot open fire. Silver has a melting point of 962°C so in theory it could be possible but it would be very difficult to get a campfire hot enough to melt silver. The fire would need to be much larger (possibly a large bon fire) and have ideal combustion conditions. Now if you use earth or stone to create a sort of kiln then you can get hotter temperatures but the question was about a typical campfire.