I haven't had a vacation away in a few years. The last one, Marley
stayed at my parents house (that was the start of his megacolon;
they found poo on the floor) and Shadow was boarded because he had
bad habits peeing on things (he hated Marley).  I wrote up these
instructions for my Mom who is staying at my house at night to take
care of Shamrock and Bonnie. Am I missing something? Am I going
overboard?

The care and feeding of my babies

Food:
Fed twice per day, breakfast they are flexible but any time between
5am - 7:30am.  Shamrock gets one whole can (3 oz) of your choice
per meal. He likes them all, just mix up the flavors so he doesn't
get the same one twice in one day.  Sometimes he likes more than
one can at dinner time (anywhere between 5pm - 7:30 pm) and if he's
still hanging around the kitchen when his bowl is empty, open
another for him of any flavor. He won't eat it all usually; just
throw out the leftover after a half hour or so.  Bonnie won't eat
the canned food so feed her ? cup of the dry (measuring cup is in
the container) 2x per day when you put food out for Shamrock.  I
also put about ? cup into the food bowl on the counter for
Shamrock, he doesn't eat much dry food but he does occasionally,
and he'll jump up there to eat it. Just put a little more in when
it gets low.  There are extra bowls I've left out so you can change
the dry food bowls every other day, or if you're feeling energetic,
just wash out Bonnie's and leave it to dry till morning after she's
finished hers for the evening.

Water:
I've washed out the fountain in the kitchen but if it looks ucky,
just unplug it and rinse it out paying attention to the lever on
the right side down in the bowl (this is the intake to the pump and
it gets gunky with fur).  You really should only have to add water
from the gallon bottle of water in the refrigerator.  The water
level can't go below that lever thingie, otherwise it will make
sucking noises.  Other water sources are located in my bedroom (a
coffee cup, keep filled with spring water from the fridge, rinse
out daily), coffee cup in the living room (same instructions for
rinsing, filling) and a coffee cup downstairs under the little
table next to the big TV (same).

Treats:
Shamrock only likes raw liver for treats, I give it to him on the
weekend. Since that grosses you out, you may skip it. Bonnie likes
the treats in the Tupperware on the microwave and she can have
about 8 pieces in the late evening before you go to bed. She'll
love you for it.

Litter boxes:
There is one in the den upstairs and one downstairs in the
unfinished room where the freezer is.  Scoop them daily (litter
scooper thingies are in the bathroom trashcan upstairs, and in the
little trashcan next to the box downstairs).  Scoop into grocery
bags, which can be found in the dispenser in the kitchen, and in
the top left drawer in the cabinet downstairs in the room with the
litterbox.  Plenty of bags, just toss bag with doodie balls into
the garbage outside when you leave.

Love and play:
I'll leave this to your imagination, and it might take a day or two
for Bonnie to get used to you being here, and not me. Shamrock will
warm up to you, he already loves you as you know from your visits.  
Watch his body language and don't let him get too stimulated
because he'll bite.  Love bites, but sometimes harder. Bonnie and
Shamrock play hard so don't let that scare you into thinking they
are fighting.  Shamrock loves the laser pointer toy and it is on
the counter in the kitchen, this is also useful for herding him
places. Bonnie doesn't seem to see the laser point so she won't
play with it. She likes her mousie toys; sort of like a little girl
playing with dolls. There is a feather toy they love, but again,
you're not me so I don't know how they'll act. It needs to go in
the closet when you're not playing with them.

Sleep:
Shamrock will sleep with you, probably. He likes to sleep on a
pillow next to your head. He also has a tendency to curl up next to
your body. Bonnie will come and go through-out the night but mostly
stay near your feet.  I'm sorry, but you'll probably wake up with
an itchy nose and gasping for breath from cat fur.  If it bothers
you, just shut them out. Those two have never cried to come in,
they just accept that they aren't welcome for that night and don't
try to dig their way in under the door.

Vet and Emergency:
The numbers are on the refrigerator. I've let the vet know I'm out
of town, but there are no issues with these two that should require
emergency, but these things come up.  Emergency is open after 8pm
until (they say!!) 8am. Right up the road, directions also on the
refrigerator. You know where the regular vet is. Emergency
situations would be a cat not peeing, not eating, but the eating
thing can just be because they miss me, in these cases try to call
my cell first and I can tell you what to look for. Injury isn't
likely, but you'll know if someone is hurt.  Please don't leave the
windows open during the night or during the day when you're not
here, I don't trust the screens. The windows can open from the top
and that is safe.  One window in my bedroom doesn't have a screen
at all right now.