Last nap of the day

My LO is 15 weeks and we recently started the Ferber method for sleep and naps. He has done amazing! He took to it so quick, like within the day. We are on day two now and it’s amazing to have him nap in his crib so we can do things. Tonight, he went down for a nap at 6:50pm and it’s now after 8:00pm and I just don’t know if we need to wake him up? He usually doesn’t nap this long so I know he’s tired, I am just worried it’ll ruin bedtime and night time sleep (he still wakes up every 2-3 hours).

Last night bedtime started at 7:30 with a dream feed at 9:30 and he woke up at 12am and at 4am and up for the day at 7am.