You should be able to bottle from a keg either warm or cold, but you need to consider first the pressure and temperature for the carbonation level you want, and then, to limit foaming, the proper liquid line length for the pressure you are dispensing at.
Let's say you want to carbonate to 2.5 volumes. The carbonation chart says that if the kegged beer is at 40 degrees F, you would pressurize to 12 psi and let it sit for a couple weeks to fully carbonate.
The same chart says that for 2.5 volumes at 70 degrees F, you want 28 psi.
The key is that, in a sealed keg, pressure will change with temperature. If a keg is fully carbonate cold, as above, then disconnected, left to warm up to 70 degrees F, and given it time to equalize, the pressure in that keg will have risen to over 28 psi simply because it warmed up. Similarly, if you fully carbonated warm at 28 psi and then chilled the keg, the pressure inside would drop.
At 12 psi, you want to dispense with a liquid line length around 10 feet. At 28 psi , you want about 25 feet of liquid line to control foaming.
There's a line length calculator here.
