Some advice. Don't let them sit there forever. I find miles and points seem to get "degraded" over time, the rules change, the point/mile requirements go up ad nauseum.
A friend of mine has a mountain of NW miles and I tell him to use them. I am assuming you have a ton of Hilton points??
Don't take too long to use them up.
Think September 11th...
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Michael
AA PLT,1 MLN Miles+
HH GLD, SCI GLD, MM SIL
LE PRESIDENT ETERNEL DE CAMAIR-CAMEROUN AIRLINES