I've been in a very similar boat, though I just race bikes. Had a baby in Dec. and similar power numbers. I typically max out at 8-9 hours until spring time, though, by two longer weekend rides and a couple of 45 min commutes.
I did a ton of sweetspot and tempo the last few winters and basically stagnated around a 330w ftp for the last 2-3 years. To try something different (and to try to build up some fitness before the baby was born), this year in November I did a 5 week block of vo2 max stuff (two workouts a week of 3 and 5 min repeats with equal rest, based on a Hunter Allen blog I read) and got a nice 15w bump in mFTP for a while. Had a big bump in everything else, too, when I went back to tempo and sweetspot and threshold stuff. 10-20 watts higher on everything from 5 mins to an hour long efforts plus way better ability to extend the time out on all of them (worked up to 3 hours at ~90% a few weeks ago).
Basically I feel like changing the stimulus and targeting something I haven't before really gave me some big improvements.
I did a ton of sweetspot and tempo the last few winters and basically stagnated around a 330w ftp for the last 2-3 years. To try something different (and to try to build up some fitness before the baby was born), this year in November I did a 5 week block of vo2 max stuff (two workouts a week of 3 and 5 min repeats with equal rest, based on a Hunter Allen blog I read) and got a nice 15w bump in mFTP for a while. Had a big bump in everything else, too, when I went back to tempo and sweetspot and threshold stuff. 10-20 watts higher on everything from 5 mins to an hour long efforts plus way better ability to extend the time out on all of them (worked up to 3 hours at ~90% a few weeks ago).
Basically I feel like changing the stimulus and targeting something I haven't before really gave me some big improvements.