I'm not sure if I'm checking the right items, but it looks like from a quick search, the UniFi Cloud Key uses up to 13W (max, which is what we should take, because if it's too much, we have left over spare), and I don't know if there's any different routers from Vodafone, I would expect so, but the ones I can find online are suggesting roughly 20W to 30W. So assuming both of these devices are in proximity to each other, you'll need a UPS or battery system that can provide at least 50W (13W Cloud Key + possibly 30W router) per hour you intend for it to last.
I can't believe any access points would use less than 5W each, so that's another 15W. They'll need to be individually powered if they're not close to the main grouping of equipment. So if you can work closer by to the equipment to access the network/internet, you can then not purchase any further equipment to keep the other access points active; only needing to keep the main group of network equipment alive instead.
Be aware that UPS typically have a power/time ratio that on raising/lowering one value, the other typically goes in the opposite direction proportionally (so needing double the power; 100W instead of 50W, means you reduce the time it can remain powered by the UPS by half). However, right at the very extremes (ultra low power or extreme power needed), this falls off and is no longer relational in that manner anymore.
I recently had a thread on something similar this, where I needed to keep up to around 30W of equipment alive, in case the national grid did reinstate and intialise the rolling blackout thing. So for my parents place I had to grab a UPS of some kind that could keep the communications equipment (internet and VOIP phone) alive (in case mobile connections get swamped). And the UPS I got (Cyberpower 1500VA/900W) has been tested and confirmed to power the devices for a little over 3 hours (just enough for the rolling blackout plans). But this UPS and other heavy battery time UPS tend to be on the more expensive side; looking at £280+ at least for a new one. Although in the case of an actual UPS over a battery backup, you could use it afterwards to keep NAS or electrical devices (main gaming rig, TV, etc) from being impacted by any sudden outages also.