My impression of SR from two trips is that it would take half-day skiing to get from one hotel to the other at the different ends of the resorts. And I mean skiing down decent runs from lift to lift, not using the traverses. We stayed at the older hotel by White Heat. The same is not true for Killington even though it is spread out in a similar fashion from Sunrise to Ramshead peaks.
You can get to the base area below the Summit from almost anywhere on the mountain, and from a decent portion of it you can get directly to the hotel (if you can get to the bottom of the White Heat lift, you can cut hard right and skate a bit to get to the hotel). It is a slog from the top of Jordan, but significant portions even of the cross-cut trails are actually fun if you don't get caught in traffic. Roadrunner and the flat (and uphill) sections of Kansas are the exceptions, but neither hold a candle to Great Eastern at Killington, let alone trying to get from Bear to Snowdon (or, if memory serves, to just about anywhere the wrong side of Skye Peak).
Getting to the
other hotel (Jordan Grand) at Sunday River is a lot more challenging; you have to ride Jordan, and getting to the hotel from anywhere east of Spruce requires multiple lift rides. It's not a long walk up from the bottom of Jordan, but if you're paying for slopeside lodging, you probably aren't doing so to have the privilege of hiking back to the hotel.
In either case, you are better off having some sort of plan when you start for the day, because if you want to ski trails on both ends of either resort, doing them in succession is horribly inefficient.