In Wellfleet, a housekeeping cottage may be the best way to go. I can't say enuf good things about Carolyn and Terry from capecodrealty.net. We've rented from them several times in the past few years and they go above and beyond. The condo/cottages are usually equipped with every kitchen utensil known to man.
We've also trolled vrbo.net, cyberrentals.net and weneedavacation.com, and had terrific replies from some of the homeowners advertising there, and have enjoyed a few good stays through these sites.
Why choose Wellfleet? With luck, you can find a place to walk to town and it's really kid friendly. There's a sense of historic small town, and it's w/in driving distance of the wonderful restaurants, history and beaches of Provincetown, as well as Cape Cod League baseball games in Orleans. The National Seashore has several visitor centers that offer everything from ranger-guided camp fire ghost story nights on the beach, to forest nature walks, to canoe lessons. And don't forget to visit the extensive land of the Mass. Audubon Soceity.
Above all, you have your choice of three types of water to swim in. When you rent a cottage or condo, you can purchase a parking pass to all the Wellfleet bodies of water, and there are many to choose from:
1. The Ponds -- especially terrific if you really want to swim in a calm, warm, clean freshwater area, as they warm up quicker than the ocean. There are at least three large ponds, at least one where yoiu can rent pedal boats, canoes, kayaks, etc. There's nothing quite like them.
2. The Bay -- I don't have enough time in the day to count all the Cape Cod Bay beaches in Wellfleet. You can walk to some, ride to others and park w/that pass. Pick one w/other families there, and you can bet they're terrific. At time of full or new moon, the tidal pulls are incredible and you can walk way out into the bay and the kids love this. The water, again, tends to be warmer than the ocean.
3. The Ocean -- There are at least three ocean beaches w/parking lots that are in the Wellfleet parking system -- Long Nook, Cahoon Hollow and Newcomb Hollow (am I missing one?) Be forewarned that you have to drag your blankets, coolers and kids down a steep dune incline at each of these, but it's worth it. The water is usually rougher, and colder in June, July and early August than the Bay. But it's often fun to just wade and watch the surfers who come out in the late afternoon.
But, hey, if you have a week, enjoy them all. We've been known to go to five beaches a day in Wellfleet, depending on wind, tides, times of day, and whether we wanted to swim, wade or veg.
When reading what the cottages supply, note that on Cape Cod, some places - even quite modern and beautifually decorated ones - still only feature a full-sized bed, and we're used to kings. Note whether the place has a phone, and whether you'll have to use dial-up to access the Internet w/your laptop. Also, it's a good thing to have cable or satellite TV, rather than just weak antenna, because you'll want to watch the Weather Channel when planning your day. Also, not all offer dishwashers or washers and dryers. As you know, a clothes washer make a huge difference of how much less you have to pack. AND the dryer is almost a necessity, since it can get quite humid on the Cape, making it more difficult to dry things before sunset.
We have to go to the Midwest to visit relatives this summer, so we're going to have to pass on Wellfleet. We'll try to do a long weekend in the fall -- the ponds are often warm through September.