As it stands, you have only one North America segment out of six permitted (one transcon) so if you wanted to pad the TP and redeemable balance a little, you could treat your PDX stop (after JFK) as the first of two allowed stopovers in the continent of origin, then sometime before the end of the RTW validity, do a weekend something like (...JFK-) PDX-xLAX-ANC-PDX for another 220 TP or so.