If you have the postcode of the intended location, check mobile network coverage as the costs might not be too bad compared with the possible expense of short term use of a phone line and broadband. Again, it depends on how much data you expect to use.
If you expected to use just a few GB (no YouTube or TV news video clips, no iPlayer, no big downloads like system updates for any devices {ie turn OFF automatic updating}) then 12 GB PAYG plus a USB modem from Three is around 90 quid (and there may be some cashback deal), and I could lend you my (40 quid) Three router that runs on mains power and can support up to 5 devices sharing the connection, has 2 ethernet sockets and provides Wi-Fi for a property). It's like their "MiFi" (the mobile, battery powered version) but better, IMHO, for household use...
I was using it with a 15 GB/month allowance and used 95+% every month, but if you only have modest needs, were in a coverage area, and didn't want any contracts, you could use Three pretty much as soon as the post can get there...
Three offers 3 GB / 3 month and 12 GB/ 12 month PAYG offers, including the USB dongle and SIM "ready to go" for around 40 and 90 pounds. Clearly these are for lowish use, and they run out as soon as the time period or data runs out (whichever is first), On Ebay you can see 3 GB pre-loaded SIMs for around 13 pounds which compares favourably against many mobile PAYG costs where some charge 10 quid for 1 GB. It would also mean that if you used 12 GB in say 10 weeks you could just add another 3 GB/3 months for a small additional charge.
You could decide after that whether to flog the USB modem on Ebay, to offset your costs, or keep it for emergencies (and buy another Three 3 GB SIM from Ebay to hold in reserve - just remember not to "test" it because the "3 month timer" starts on first use)