Done it 10-15 times. You won’t have a problem. Inform them at the rental counter but I’ve never had a problem.
Advice for others: only time this is a problem is a Canadian driving a US-plated car into Canada. Canada doesn’t allow this (tax reasons.)
Unfortunately, you won’t get a definitive answer here because this policy can very by agency and even station. I’ve seen this before.
You will have to call the pickup location specifically* to verify that they allow cross border travel and what, if any, condition apply.
If you cross the border in violation of their terms, you are not legally in possession of the car. This can create legal and insurance complications you don’t want. The biggest risk is not having valid insurance.
I’ve rented 100’s of cars. I would find the best deal online, book it, then call the location. Just be sure there’s no cancellation penalty.
*I know people don’t like this answer, but it the only realistic way the OP can be sure since each station can set their own policy on this, there is no one single corporate policy.
Credit:stackoverflow.com‘