If the connection gets hot enough to melt solder it may melt the insulation as well.

I like to crimp and then solder the connections. The solder keeps any moisture out and prevents corrosion. Downside is it also makes a stiff end.

If you are buying able in Germany it may be far more expensive.

Be sure to look up the equivalent wire size. They don't use American Wire Gauge - they use cross section square millimeters.