We gave our son a 7 night air/travel package to Hawaii. Can we cancel the hotel side of the trip and take it later in smaller increments at different locations, say 3 nights, 2 nights, 2 nights at other Marriott hotels with the same category level?
Yes and No. You can cancel the 7 night hotel reward and use it at a later date (I believe they expire a year after issue but you can usually call and ask for a one-year extension). Marriott will also allow you to change the category level of your redemption (say for example you initially used points for 7 nights in a cat 7--you can usually downgrade that to a cat 6 or cat 1-5 redemption and get some points refunded) However, you cannot break up the 7 night reward into different increments. Marriott used to have an island hopper award for Hawaii that allowed you to do this, but that offer went away a few years ago.
You may want to call customer service and ask. Every time I have used the 7-night package, the reward actually showed up as one 5-night e-cert and one 2-night e-cert. I don't know about splitting it beyond that, but if you talk to someone, they may at least allow you to apply them to two separate stays.