When your child goes down to one nap per day, the nap they do take is usually longer than the ones they used to take, so you may find that you still have a good span of time to get things done. My 20mo son takes a two hour nap every day so I feel that I really get a nice break in the middle of the day. I use his nap to shower, read, nap myself, work on homeschooling with my oldest son, doing big things around the house like polishing the hard wood floors etc... I save the regular chores for when baby is awake because he loves, loves, loves to help me with them.
Try to encourage her to help you with things like laundry. My little one and I do laundry together and make of game of seeing if he can correctly name the person each article of clothing belongs to before he tosses it into the dryer for me. We have front loaders, so he also helps me load the washer. I then add the detergent for the washer and he adds the dryer sheets for the dryer. I also let him push the buttons (under my direction) to start the washer/dryer. He adores helping (they all do at this age) and will also hand me items from the dishwasher to put away (after I have removed all knives of course), helps me close and start the dishwasher, "helps" me vacuum by riding around on the vacuum etc.. Helping out is very educational for the little tykes so let her help and use her nap for the things you can't do when she's awake, like reading a little bit of a good book, etc.
Once you get into a rhythm it'll start to seem like you have vast stretches of your day with nothing to do but play with baby, which is of course just the way it should be. :)
Also, for things that need peace and quiet, like e-mailing and working on certain projects or school work, I stay up after the kids are in bed and handle it then so I can sleep until they do in the morning. Since the kids go to bed at an early hour and need a few hours more sleep per night than adults do, I still get plenty of sleep.