At normal human speeds, the required AoB for a rate 1 turn is simply approximated by knocking the last digit off the TAS and adding either 6 or 7 depending on which you prefer - 90 Kts gives 9 + 7 or 16 deg Aob (so fly to 15) 120 kts gives 12 + 7 = 19 Kts (so fly at 20).
Not sure how well that works when you are doing Mach 3 at 35000' and your TAS is in the region of 1800 Kts
Circa 30 nm/min makes for a big turn but not Canada to Mexico....