I mean, how much do you value accurate steering and non-abnormally worn tires?
No one can really give you a specific mileage or prediction of exactly what will wear out and how fast.
You're changing the suspension setup, so you need an alignment, that's not a question. Will it result in a horribly off center wheel, resulting in maybe the steering angle sensor not being happy and setting a code? Maybe? Maybe Not? Will it result in heavy feathering and/or abnormal wear on your tires as well as annoying handling? Probably? Will driving it 100miles or 1000miles ruin said tires? Maybe?
There's a ton of variables there that no one can really account for, not including how much you fiddle with the LCA cams, and tie-rods installing the spacers and trying to "eyeball" the toe-in.
Only way you'll know is after you install it and drive it, if it's something you can live with for a bit until you get your alignment, cool; otherwise you may just want to wait until you can get an alignment done after the install?