I would run the oil longer rather than have a quick lube place touch my car. You'd be surprised how stout modern oils are, especially with your large sump capacity. It'll be fine especially since this sounds like a one-time situation. I know you just downsized, but the tools needed to change oil can be purchased surprisingly cheap... filter wrenches, drain pans, box/ratchet wrench, rubber gloves... maybe a screwdriver or small wrench to remove shield/access panels. You don't need ramps, use a driveway/curb arrangement, set the brake and lay down an old towel. If you're looking to have someone else do your oil changes for the long-term, find a local reliable garage (not a quick-lube or dealership)... you bring the materials, they do the labor. This is probably the next best alternative to doing your own oil changes. Good luck.
