I need a constant internet facility at my holiday flat in order to use
the Hive setup to remotely monitor the temperature and to turn the
heating on prior to each visit.

I'm currently paying for a landline plus ADSL broadband at a total cost
of about £250 p.a. (and the ADSL will go up in price when the current
contract ends). We have an Evening and Weekend calls package for "free",
but daytime outgoing calls are made on a mobile, and E&WE calls could
easily be, too. We get a few incoming calls - but most people seem to
have inclusive packages which include calls to mobiles these days, so
our friends shouldn't be too upset if we got rid of the landline, so
that they had to ring a mobile instead.

I'm wondering about getting something like this:
https://www.amazon.co.uk/D-Link-DWR-...016ZWXYXG?th=1
to provide 4G-based broadband. Since it has ethernet ports, it should be
possible to connect the Hive hub - which can't use WiFi - to it.

Do any of you have any experience of getting rid of a landline and using
something like this?

Are there any gotchas when it comes to data SIMs? For example, PlusNet
told me in an online chat that their SIMs can be used in phones or
tablets but not routers - but I'm not sure that the agent knew what he
was talking about.

Since our data use is fairly small - no more than 1 or 2 GB per month -
something like this looks promising:
https://www.amazon.co.uk/Three-Mobil...HDPN1WZDP6N5AM
since the data doesn't expire for 24 months. There is a reasonable '3'
signal at the flat. Any reason why I couldn't use one of these SIMs -
and then top it up or replace when the data is used up?
--
Cheers,
Roger