I work in a small team in a public sector organisation. We have recently got a new team leader. This person has no children or caring responsibilities and seems to have a very different attitude to work-life balance than their predecessor. They are expecting me and the rest of the team to travel regularly to offsite meetings around the country, which means either overnight stays or getting up very early/returning late. I have primary school age DC and no extended family I can rely on for help, so if I need to travel for work this means a lot of additional load for DH (who is a great and involved dad but also has a busy senior job), and it also means I don't see my kids - they are asleep when I leave the house and when I return home.
The boss now wants to plan a multi-day team planning meeting in a destination I will need to fly to. Initially they had planned this to take place in the school holidays but I said that was difficult for me due to family commitments (I was planning to take annual leave the week in question). They now want it to happen the first week of the new term, meaning I would literally be missing my DD's first week of school. I'm the only one in the team with DC and feel like no one understands the constraints. In other teams and organisations I've worked in it's been generally understood that important meetings and work travel shouldn't be scheduled during school holidays.
I am also part-time working 4 days a week, and the new boss has also been muttering about this, I am already coming under pressure to attend meetings on my non-working day.
Basically, how do I discuss flexible working and family commitments with someone who seems to be not at all sympathetic? When I was hired for this role they mentioned a requirement for "occasional travel" but that wasn't defined. Before the new boss started I was traveling 1-2 times a month day trips, and overnight stays very infrequently. Now it's day trips about once a week and overnight about once a month. Am I being unreasonable in expecting that I shouldn't need to regularly give my family time to my employer?