I have 12mb interner via MEO ADSL and there is sometimes a bit of buffering when watching UK channels. Don't forget that FilmOn is a rebroadcaster and if their servers are busy it will affect picture quality.

I can usually get BBC and ITV main channels via a proxy and they sometimes buffer as well.

But not for a couple of years yet! And the word is that BBC will ask for a TV licence number etc to be input for short term holiday access from a non UK location.

Also of relevance is a plan to end mobile roaming charges within the EU by the end of 2017. Hard luck if you are Swiss, or if the UK votes to leave the EU.

Heads up.
Further to my post above, the changes took place on 1st September.
There are reports around that iPlayer no longer works with a VPN when you're abroad.
I use Media Hint when in Portugal but I can't test that until we arrive on the 12th.
Meanwhile, here in the UK, we've lost iPlayer via our Humax Freesat Box but there are reports that the BBC are working to fix this issue.
Will wait & see.
Only BBC iPlayer is affected - ITV, 4OD etc all still working fine.

I have been unable to BBC iPlayer when in Portugal even via a VPN since early July. Things may vary for individual situations, but the IP addresses used by VPN services are not difficult to determine and thus block. 

Was still working via Media Hint when we left on July 19th.
Still a cheap option at $3.95 a month payable monthly via PayPal - no long term contract.
I only pay for it when were over.

Their website currently shows BBC iPlayer as being available - will find out in 10 days time

https://mediahint.com/

Our UK Freesat issue has been fixed.

Sorry, forgot to give an update.
Yes everything is fine via Media Hint - no problems at all

An update - my apple tv which i use for bbc live said i was outside uk despite using a router with vpn settings - i then connected this router to an apple time capsule (which is a hard drive back up and a router) and this has confused the iplayer which I can now watch!