That does sound promising!
If you got 1 bar (even if not always) at ground level, then usually you should get an even better signal (maybe 2 bars or more) upstairs from the house - with 4G, the higher the better is usually true.
It's a shame you didn't run a speed test.
Yes, due to the data caps, 4G is expensive. I currently have a 32Gb per month SIM-only rolling 30-day contract. The usual EE Data SIM-only details are here: EE Data SIM-only
(I'd choose "30-day" plans) - but I managed to find a special half-price deal on HotUKDeals (HotUKDeals EE
) around a year ago now - paying £14.50 per month for the 32Gb. As a "turbo boost" (plus backup link) for my 2.5Mbps ADSL, it works quite well. HotUKDeals do have periodic special offers on Data SIMs that people come across.
Also, EE do special Mobile Broadband
packages, with much higher data caps (up to 200Gb) - but not SIM-only, these packages include a router, plus optionally EE's own external aerial. It can get quite expensive if you are adding these to an ADSL package! However, you can opt for a 30-day contract (which I would advise), although you have to pay £99 up-front for the router. A shame as you already have the MR200! It would be nice if EE did a 200Gb SIM-only deal.
Don't forget - the TP-Link Archer MR200 is unlocked, so can accept SIMs for any of the mobile companies, EE, Vodafone, O2 & Three, so it may be worth trying a test SIM of the other networks at some point.
At least you now know you can get a 4G signal at the property using the 4G router (probably a better signal upstairs from the house too), so it gives you a reasonable backup option. Hopefully 4G data allowances will increase over time too.
I wouldn't want to advise you either way on whether to go ahead with purchasing said property though, based on just that!
The FTTP situation does sound quite optimistic too.
I understand that a standard ADSL link that has a downstream speed of 2Mbps or more, can stream SD (standard definition) video reasonably well (although 3Mbps or higher is probably recommended).
So - in summary - it does seem that combining an ADSL link with 4G (e.g. via load balancing) *could* be a viable option.
Maybe other forum members can add their advice to this?