We have DS3 and DD1. We still find going out with them for whole days tricky and tend to go out in 'bursts' and visit a local park or nearby petting farm - and even then it's far from glitch free!
I know you shouldn't compare - ever. But...I feel that we don't do 'enough'.
Quite often our days are resting and doing absolutely nothing due to a terrible night's sleep.
Our peers with two kids of a similar age - and many with one extra - seem to fare better.
I don't want our kids to miss out.