IIRC the rule has always been that the miles cover a one class upgrade, including connecting flights, but of course there must be upgrade fare class availability. Assuming that the transcontinental flight has no PS cabin, the miles *should* (I've never tried this with a domestic D1 flight) cover both segments, but do not assume that upgrade spaced is available. This assumes that you have a single ticket/PNR and a single fare component (with no stopovers?), which might be an issue (did DL split the fare?) to get you both W and G segments. My suggestion would be to look at the fare calculation line on your receipt very carefully before calling DL to determine whether or not you have a through fare or a ticket with broken fares.