Work change

My employer is attempting to change my role to weekly travel expectations. Multiple places I travel to are 2+ hours away. If I have an expectation to be on site for say 6hours and my work day is 8 they are saying they will pay my hourly travel there and offer a hotel. If I refuse the hotel they won’t pay my travel back same day, just mileage. They also have the expectation I complete multiple overnight stays per month with no additional compensation.

Above and beyond refusing the work as it’s not part of my contract (although it did have that annoying “and any additional duties assigned” clause).

What can I do??