That must feel very satisfying, successful startup and first ride.
You mentioned having trouble keeping enough heat in the engine. There is a fix for this, (a fairly contentious fix, at that) Watt-man Thermobob, which converts the real basic KLR cooling into a proper thermostatically controlled bypass system, just like 100 million car and truck motors.
Have a look at the data on watt-mans site and make up your own mind.
On my thermobob equipped KLR the temp comes up to normal (about 30-40% of the range) and STAYS there, regardless of load, speed or externql conditions.