As an old time landscaper I can tell you there is no groundcover that chokes out weeds. You have a choice. Return from a trip and spend hours pulling weeds out of groundcover in 100 degree temperatures or retaining your present lawn and hiring someone to mow and edge. May I suggest the latter option. It is the least frustrating method for a busy person. If you do not have an inground irrigation system, install one. Costly, yes. But the practical solution for your lifestyle.

You have many deer proof plant/shrub choices. Strongly suggest that you do a search for, garden coaches + Atlanta, Ga. There are some excellent ones in your area who can assist you with advice at a less costly rate than landscape architects. Working with one of them will save you time and indecision.

I have to agree with nandina. My next door neighbor (adore her!) bought her house thinking it would be lovely to NOT have a yard to mow. She has mulched paths and perennial beds with low maintenance plants. It is pretty when it is taken care of. She doesn't travel, but is a busy realtor, running around here and there.
Her yard has gone crazy. The beds are full of crabgrass; the creeping groundcover which was once just in one area is now everywhere! It has gone nuts and she just doesn't have the time to maintain it. Mowing a lawn would be a piece of cake compared to what she has to do.
Personally, I prefer the whole "no grass" scenario -- but I LOVE to garden and I am out there all the time, whenever I can. Even low maintenance plants require a certain amount of housekeeping.
Whatever you do, be it keep the grass -- or replace with something else -- it will need love and attention!
If you really are gone a lot, you will need someone to help -- either a lawn mowing service, or a gardener.

I hope that doesn't sound discouraging! :)