I agree with Dorsetduckowner about the bio security - moving home is hugely stressful for any kind of poultry, and if you were going to board them for just a week or two, they would be stressed for that time, and then again on their return, having just begun to settle in. Stress depresses the immune systems of poultry, so then they are much more likely to succumb to latent illness they might otherwise have overcome naturally, such as mycoplasma. They are also a risk of fresh infections or infestations gained from the place you leave them. However nice and clean it may look, there will be bacteria and viruses anywhere there is a succession of poultry moving in and out, from different environments, not all of which will be ideal. Whilst your own birds may be resistant to the strains they are used to, they can still be challenged by a slightly different viral or bacterial mutation, which can then possibly take root in your flock thereafter and emerge subsequently, especially mycoplasma.
I'm not saying that boarding will inevitably have these results, but you need to know that there are vey real risks, and if possible its best to cultivate a friendly neighbour who can do the basic care in your own home. I have a friend down the road who keeps chickens and we just look after each others birds when we go away, which is great. Sometimes I 'employ' his teenage daughter, who does a good job for pocket money, and she has adult backup if its needed. So maybe training up somebody like this, giving them some practical sessions and written instructions, plus your mobile number and the details of the vet etc, might be a good way forward long term. It means you can plan for shorter weekends and holidays as well, without all the upheaval of moving the ducks and then collecting them.