Newbie AG Kettle Volume Q

So im brewing a blonde ale AG batch. My question is if you mash and sparge with more water than the volume of your boil kettle what should you do?
Should you collect all the mash wort in the kettle, and then add as much sparge wort as you can without overflowing? Or should i boil in 2 seperate kettles? Or would it be best to mix all the amounts together, and then take as much of the wort as i can and put it into a boil kettle so the portions are equal?

how big is your kettle? what volume are you shooting for? do you have two burners?

Had that issue for a while. 7.5G kettle doing 5G AG batches. I'd put my first 5.5G into the kettle and start the boil. Drain the rest of the sparge into an ale pale and slowly add it to the boil throughtout the boil time. Made for a really tedious brewday until I got a 15G kettle.

Im using stove top. My kettle is 6Gallons and im shooting for about a 5gallon batch.