what do you snowbirds do when you leave home

Another freezer idea. Put a bowl of ice cubes in the freezer. If you have a power outage that could result in spoilage of food, you will know it when you return and your ice cubes have melted and refrozen in the bowl.

Make sure the house is monitored by a security company with temperature or that someone stops in once a week or so, especially in cold areas. We made a trip home and stayed at our old neighbors house because they were in TX for 3 months.
Furnace had quit working and it was 40 in the house when we arrived. Person who was supposed to be checking house and feeding kitties hadn't been there in awhile. Make sure you can trust the person to actually check on the house/pets.

Here's a special one to add to the list: If you have a freezer full of food in the basement, don't turn that circuit breaker off! Wasn't me - it was my parents many years ago. It took a long time to get rid of the smell.

We forward mail.
Have city turn water off, that way we don't get billed for water, sewer, or garbage pickup.
turn heat down to 55
Put timers on lamps.
Unplug tv's & unused lights etc.
Change battery in thermostat before we leave.
We used to unplug fridge with the door ajar, but now leave it plugged in, as it's a new energy efficient one.
Leave the dishwasher door ajar.

1. All the suggestions from other posts are great. I would add a few more.
Stop your daily news papers a week before you leave so as to make sure delivery has stopped,
2. Go to the post office and have all your mail forwarded to you winter address, put a plastic tub undeneath the mail slot to catch all the mail that does not get forwarded to your winter address.
3. Measure the height of each of your windows (the channels), cut some pieces of 1x 2 to the exact window measurmet, put each piece in place. A litte more safety from home intrusion.
4. Call your local police dept. and ask if they have a volunteer group that will provide home security visits/observations of your home. We have a group called VIPS (Volunteers in Police Service who have to go through about 30 hrs. of training with the police dept.) who will put your home on a list for routine checks. If anything is wrong, they will call you and the police dept. This is a free service but I always give them $100 for a winter season.
5. Go to bank and have all your important bills payed automatically, ie. house payment, heat, water, insurance , Dish TV ,internet service provider, etc etc

We have well water not city water. We use an air compressor to blow out all the water lines, I rigged up a small tank that lets me use air pressure to blow RV anti freeze through the refrigerator, dish washer and washing machine so the water valves wont crack. You may get all of the water out of those valves with just blowing air through them. Maybe Im too nervous but I did crack the ice maker valve one year.
I then put windshield washer solvent in all the traps and toilet bowls. I have two aluminum door awnings that I place a 2x4 props under so the snow load doesn't tear them off the house. I turn the propane off at the outdoor tank. I used to shut off the main elec breaker but this year I'm leaving a few circuits on for video surveillance cameras and yard lights.
Update. Brother in law is staying there this year. Very easy.

We sold ours :-)

We have been wintering in Florida for 5 years with no problems. Everyone does it differently depending on their circumstances. These are things we do for our situation. In no order.

Forward mail.

Turn the heat down to 50.

Open all cabinet doors under sinks.

We shut off the water to the washing machine, refrigerator, outside spigots, and toilets. We leave the house water on due to forced hot water heat.

Shut off boilermate. (makes hot water through furnace)

Add RV antifreeze to toilet bowls and sink traps. (It appears to help keep the water from evaporating as we have never had a problem.)

Heat is monitored through alarm system. Sends signal to central station at 40 degrees. Our oil company has 24 hour service. We have a key hidden outside. We will tell service person where it is located if needed.

Have house checked by relative every 10 days to 2 weeks. He just does a quick walkthrough.

Turn on security system. Notify central station that we will be away for 4 months.

Check security cameras from Florida every day or two.

Several lights are on timers.

We have driveway plowed.

I hope this helps.
Paul