This is not recommended. Different rooms have different heat loss characteristics and heating requirements, while a thermostat can monitor the temperature in only one location using its built-in or floor sensor.
For example, if one thermostat controls the underfloor heating in both a kitchen and a bathroom, with the sensor located in the kitchen, it will regulate the temperature based on the conditions in that room. Heat gains from sunlight, household appliances, hot water pipes, and occupants may keep the kitchen comfortable, while the bathroom could remain too cold—or vice versa.
An exception may be applications where all areas require the same temperature, such as cold storage rooms.