Originally Posted by hhoope01

The miles are put into your airline account of choice. After that the use of those miles are totally up to the rules of that airline's program. Marriott has no control or even visibility into how you use (or don't use those airline miles.)

You will also receive a 7-night hotel cert of which you will have 1-year to use at any hotel you choose, within the category level of the hotel cert and hotel award availability of course. Marriott will normally let you extend that hotel cert for up-to another year (essentially giving you up-to 2 years to find a hotel to use it at.)

There are no rules linking the use of the airline miles to any particular hotel or hotel award reservation. So yes, you can sit on the free nights for at least a year and usually up-to 2 years.