You folks in the States have smaller deer than up here in Canada. Known FACT in my area.. be particularly alert dawn and dusk when they like to move...AND...you won’t hit they first one...look for the buck following is the kicker.
I was in Newfoundland last summer...moose are MUCH BIGGER...and move at anytime of day.
A deer whistle is a slight deterrent,won’t stop them,but they will pause for a second to determine what the noise is...gives you an extra second to figure out what you are going to do. BUT if your number is up...it’s up.