I vote to brew one of the more typical, 'bigger' beers to the completion as indicated by the "iodine test" and assess those pre-boil numbers.
This is going to be particular to your system and processes. There's a lot of overlap in what all of us do, but we all use different equipment and we all have different tolerances for just how hardheaded we will be when something isn't quite right, like missing the numbers by just a bit or something like that.
I mash to the numbers myself. If I miss because of low efficiency, I can grab some more malt, grind it up and fix it there. Then figure out what happened later. Hopefully. I could just go forward and boil off some overhead wort too. I mash and then sparge to 8.25 gallons, boil to 6.5 and t/f about 6.2 of that. By the time I've harvested yeast, drained out the trub, I typically have about 4.75 gallons of big hop IPA or about 5.75 gallons of lager. Ish.
If I have the 'overshot my numbers' problem by the end of the mash, this is a good problem to have. I can just cut it to the gravity I want and end up with > 5 gallons. I have spare 2.5 gallon kegs around to handle that.
I forget which brew it was but it went something like this:
mash was about .010 low. I'm already 90 minutes in, and have not mashed out!
added a pound of freshly ground 2 row.
mash now about .005 high.
overshot the sparge. DOH! had 9+ gallons
boiled longer / before hop schedule.
kettle heater element overtemp fault.
resume boil
finish
have almost 8 gallons of of beer.
It was a PITA brew day, but I was able to achieve success and the beer was as expected so, I'll call that one a draw.