I think it really depends on the person/people involved.
Too much land isn't really too much if it's viewed as wildlife habitat in my opinion.
Just keep some trails mowed and keep a check on certain invasive plants. I find it enjoyable to let the wilds take back over some otherwise abused hay fields. Seeing the amount of pollinators and wildlife going about the wildflowers is amazing!
I think a little precision cutting back here and there will maintain the essence of a woods/wildflower meadow.
Personally I like the idea of more (only if you can easily afford it!) because there is the opportunity of options. Future woodlot, grazing land, etc...
But "more" to me might be a drop in the bucket to some
Where I'm sure there are also plenty of people who think anything over an acre would be too much!
For me, the sweet spot is somewhere between 10-30 acres, I chose on the high end of that and glad I did. Not a problem for me to only focus on a small portion for projects and let the other areas be your wild buffer zone.
...Fencing costs should be considered but luckily our entire property already is surrounded by 8" cedar posts!