Actually, there might an even more accurate way of doing things ; counting how many different athletes/teams has won a medal in an olympic event during the olympic cycle (so not exactly the last WC medals table, nor the total medals one which counts the same athletes/teams over and over)
Apparently, this is how the french national sport agency is estimating the country medals chances. This cycle, they found out 107 podiums, and they assume a 50% convertion rate during the olympics (so 53-54 medals overall).
Here @Sindo, some works for you for your hollidays