watchdog interaction with sleep

I’m using something like this with a moteino/anarduino type of board and getting more reboots than I should. I suspect something is not ok about using wdt disable/enable cycles like this.
Can anyone give me some advice on it? It mostly works, just some unexplained reboots when there is a lot of interrupt and processing activity.

void loop() {
wdt_enable(WDTO_8S); //wdt will cause reboot unless we disable it in <8sec

if(pinChangeInterruptFlag) { // we can get interrupted any time, but mostly just 8 second sleeps and wakes
do_small_stuff() //takes a couple of seconds or less

if (extraStuffNeeded ){ //happens sometimes. uh oh, this might take 6 seconds…
wdt_disable(); // so lets give ourselves another 8
go_do_extra stuff();
pinChangeInterruptFlag = 0;

LowPower.powerDown(SLEEP_8S, ADC_OFF, BOD_OFF);

Posting small sections of imaginary code is not helpful.

Posting code that wont compile is not helpful.

Are you able to post the actual full code that causes the problem ?

I'm really just asking if anyone knows whether watchdog timer enable/disable usage is likely to have a conflict with lowpower.powerDown sleeps.

The full code is too big to post and somewhat proprietary. The code compiles and runs just fine for the most part. I wouldn't ask someone to look through the full code.

The sample "imaginary" code should be enough for someone who knows about both the wdt functions and the lowpower lab functions to make a judgement or suggestion that a usage like I am doing is ok or not ok.

If you don't know about those things then posting more extensive code likely won't help you answer the question.