I've done this for many business accounts, and the same should apply for residential. Verizon has different tiers depending on the area, but regardless the lowest tier will always be the same price. It doesn't matter if the lowest speed is 75/75, 100/100, 200/200, or 300/300. All you need to do is call them and ask to be upgraded to whatever the new lowest tier is and it won't increase your monthly cost.