Even though you have a basement I would still run the floor heating element through the ground floor, I think it will be tricky otherwise.

I am a bit jealous since here we have only air to air heat pumps, standard for Mediterranean because mostly used for cooling rather than heating but much less energy efficient than ground to ground.

It's good to diversify though and have a number of different solutions that can overlap instead of putting all your eggs in one basket, even if any one solution doesn't provide 100% coverage of your total needs.