We're making due with a tiny bar sink which is actually a lot smaller than the nearby bathroom sink. What helps is having a wand sponge thingy to clean whatever dishes we have. I wouldn't bother adding a temp sink.

You could rig up a portable sink like this in the back yard. Water supply could be a garden hose, and the drain could be routed to some part of the yard that would appreciate the water.

http://www.amazon.com/Portable-Camp-Cleaning-Table-Faucet/dp/B00AM23N3M/ref=sr_1_8?ie=UTF8&qid=1379629357&sr=8-8&keywords=portable+sink

more convenient link format

Here is a link that might be useful: portable cleanup sink

We used the laundry tub in the basement.

I used paper everything...

I agree with what gaucho, debrak, and Joanie said/suggested. You have good intentions with your temp kitchen set up, but if you are like us it will be so much easier to eat out. Good luck!

This could be a good time for you to install a set tub (AKA laundry tub or utility tub) near your laundry area. Especially if your washer is in the garage, these things are endlessly handy: get the garden off your hands before you come in, hose off the kid who's too filthy to cross the doorstep, fill the bucket with wash water for floors or car, rinse off the beets you just picked in the garden, etc. And, of course, a sink to use during reno.

We actually cooked a lot. Used the upstairs bathroom sink to wash. Used disposable plates/utensils. Grilled a lot. Found 101 uses for non-stick foil

We used the bathroom sink for 3 months. Luckily our vanity counter is long enough for a drying rack. It was better than washing in the tub. We used paper plates, but regular bowls and flatware. It really wasn't all that bad.

How would you get hot water to an outdoor sink? You could drain it to a 5-gallon pail, and dump it on flower beds.

I continued to cook as much as I had when I had a kitchen. (I only like restaurants I can't afford! ;) GC was willing to set up a temp sink in my temp kitchen (the playroom), but that would have involved cutting holes in the floor for pipes, and the sink would have taken up too much space anyway. So he set up a sink outside, very close to the temp kitchen area. The hose was hooked up to it, so cold water only, and the waste was directed into the yard, away from the house. The water always tasted like hose, so we got any water used for cooking/drinking from the powder room, which grossed me out, but we survived. Good luck with the reno process!

Here's an older thread that I remembered:

temporary sink

Here is a link that might be useful: temporary kitchen ideas on GW

We used our laundry room sink while our kitchen was out of commission. We did try to minimize the amount of cookware and dishes that we were using. Paper plates and cups. Did lots of grilling of meats and veggies.

The laundry room sink was also good for cleaning up tools after drywall patching and brushes and rollers after painting.

We added a laundry sink right before we began the tear out. We'd been wanting one, and it was a good excuse to put it in. Now that the kitchen is done, I still get a lot of use out of the laundry sink and don't know how we ever lived without it. It's also nice that DH has someplace else (besides my new kitchen!) to clean up his greasy hands after working on his motorcycles. And it's perfect for bathing our little pup.

We have been working on our kitchen and bathroom off kitchen for 3 years. DIY and it has been slow and in spurts. We tore out kitchen to the walls, but left a small section of counter right around the sink so it was usable. We got the bathroom functional last December, but instead of installing the vanity, we put in a laundry sink. That's what we used after we tore out the last of the counters (and sink) in the kitchen in January. (Needed to tear up the floor and fix the subfloor.)

Thank goodness we had the laundry sink, as we just got our kitchen cabinets mostly installed last week and put the kitchen sink in over temporary linoleum covered plywood counters. Had a wedding over the weekend, so needed to use the kitchen. Might be a while till we get the counter-tops and floor installed.

Anyway, it's great to have a laundry sink but if you don't have one handy, I think I read on here that someone installed a cheap tall kitchen faucet temporarily in the bathroom. They said it made it easy to put a basin/washtub under it and to fill up pots and such. Seemed like a really good idea. Maybe that would work.