Standard temp at FL370 is -57C. 2C warmer for every 1000' lower.
Std at FL350 would be -53C.
It's not uncommon to have ISA+10(-43C) at altitude.
Slightly warmer then ISA+10 is not unusual but warmer than ISA+15 in the mid 30's would be uncommon.
Many jets have tire temperature displays. My recolllection is that the tires typically are not below 0 Celsius during cruise so they might be adding a slight temperature modulating effect to the wheel well temperature.