Jetset 88.
Yes, your memory serves you well. The speed we slowed to was 200 kts, and yes that often took the temperature out of the critical range. Also, when it was a little warmer, say +7 deg, and you entered cloud, you put the icing on. This slowed you a little, the temperature dropped to +6 deg and you had to slow to 200 kts! It must be quite rare for a crew of any aircraft to be so reliant on a tiny needle movement on a small gauge.