A bus is meant to interconnect multiple devices, so you can have two (or more) sensors on the same I2C bus (up to 127 devices).
The tricky thing is how to explicitly talk to only one of them, and for that reason I2C devices usually have an assigned address.
Some sensors/sensor boards have some means to set the address in order to have multiple of the same kind connected and still being able to distinguish them.
For that reason it would be good, if you could be more elaborate about the sensors you are going to use.
But even if your sensors share one fixed address, you could use another pin to mutually power/enable one of them at a time.
Having said this, my proposal from above to use Serial2 instead of RX/TX Serial1 is not an option, since you need D0/D1 for I2C.
But you might not need serial after all when reading the sensors with the Core direct, if you can clarify how exactly you mean this
How exact does same time have to be? Will a few milliseconds make a difference?
All the time is not possible anyway, since communication alone and linear program flow will inevitably incur reading gaps.