New technologies such as Passivhaus, ground source and air source heat pumps are also changing the heat landscape quite a bit (if on a small scale at the moment).
It astounds me that new developments still get white steel atrocities strapped to the walls, among other things like white plastic UX-disaster thermostats.
You can do electric underfloor upstairs but water is a no go upstairs unless you are concreting. The best balance is water based underfloor downstairs, underfloor electric in upstairs bathrooms + a heated towel rail (water or electric) and then water filled radiators upstairs that either run off a traditional boiler or an air source heat pump. You could use a ground source heat pump but, depending on how far north one is this can land up freezing the ground and creating a kind of localised permafrost unless you run the system backward in the summer. You could also use solr thermal if happy with balck panels on the roof.
https://www.thisoldhouse.com/ideas/retrofitting-radiant-heat...