I have 4 - all teens/adults now.
The eldest was 5.5 and middle one was 3 when the DTs were born.
We had zero family support as we lived hundreds (at one point several thousand) miles away from both sides of our family so we were completely on our own. We coped because we had to - there was simply no-one else to do the school runs, make the pack lunches, help with homework etc.
Some things we did to help were we were choosey about extra curriculars - they all had swim lessons, and then all did scouts/brownies/guides and speech & drama as standard when younger. (Not all at the same time - eldest had aged out of swim lessons by the time the younger two got there for example) Everything else was considered - we had seasons of gymnastics, ski lessons, cross country etc, but we were very picky and things were only done if they worked for the whole family. (ie. They didn’t involve me driving across the city at dinner time with 3 younger siblings in order to accommodate eldest going to a 1hr club at 6pm) We prioritised things which were walking distance or within a 5/10min car journey, and we said no to a lot of things.
I was a SAHM and DH worked his hours as best he could to be around in the evenings. He generally left very early and was at his desk in the office by 7am, which meant he left at 4/4.30pm and could be home to help with tea time/homework. If he had to log on again in the evening then he did it once the DC were in bed. As they got older that was less of an issue, and there were certain times of year when it didn’t work, but it worked for the most part. Now that they are all older he actually works away a lot, but they are very self sufficient now and I am very flexible and available. Work travel would not have worked for us when they were small.
Our weekends were pretty sacrosanct when the DC were younger - other than swim lessons on a Saturday morning, and birthday parties, we avoided other weekend activities that didn’t involve the whole family as this meant we could prioritise family time.
We also allowed ourselves a lot of grace - we recognised that our lives were just very different to families with 2 DC and grandparents around the corner so we didn’t over commit to things that didn’t really matter to us. Having said that, we have always been committed to a church wherever we’ve lived so our DC have also seen us be outward looking instead of solely focused on them. They have been invited into that though rather than it being something we did aside from them. This has always been a focus of our weekends and has invited other people into our lives which has been good for the DC, esp in the absence of wider family. (Not necessarily to support us or provide babysitting/childcare, more just as other people in their lives)
We bought a Volvo XC90 when i was expecting the DTs and still have one now.
We are all still very close as a family which is lovely to see, but I know is never guaranteed.