Is there any plan to migrate to higher temperature superconductors which might not require such low temperatures?

They introduce their own problems. They're typically brittle ceramics, making them hard to work with. They're more expensive to manufacture. And they have a lower critical current density (i.e. there's less current they can carry before losing superconductivity).

The Future Circular Collider is looking to switch to niobium-tin from LHC's niobium titanium. https://en.wikipedia.org/wiki/Future_Circular_Collider Unfortunately they'll still run at liquid helium temperatures-- while advanced superconductors have higher critical temperatures, the critical field (magnet strength) still goes higher as the magnet gets colder, and that's the figure of merit for collider designers. http://hyperphysics.phy-astr.gsu.edu/hbase/Solids/scbc.html

This is why you see new fusion reactor designs like the SPARC which use HTS superconductors throughout still use mildly exotic cryocoolants like liquid hydrogen-- not as expensive as liquid helium, but still better performing than liquid nitrogen. (Not to mention that liquid nitrogen is annoying in nuclear applications: it's easily activated by neutron radiation and deposits monoatomic carbon dust through your cryocooler circuit)