The big challenge with schedule is not regular season - you play chunks of 4 games home/on the road - made easier if schedule expanded and a second bye added during CBA. All games would need to be 10am or 1pm ET too and Thursday/Sunday/Monday Night Football wouldn’t be possible in London and fit in with US TV schedules. The challenge more comes if the team ever made a play-off and then logistics need to be arranged on short notice and with limited recovery time.
The rest of logistics whilst needing to be thoroughly planned - East coast training base, moving 2 or 3 teams to a new division etc - aren't insurmountable. Given our forthcoming General Election in the UK, probable Brexit, and need for a trade deal with the US, this would be the best time to agree tax and visa implications with our government to overcome those associated hurdles.
But then we move on to the sporting considerations. We all have teams here we support. I'm not going to give up the Rams to support a newly relocated team. I would consider a season ticket but this would need to be significantly more competitively priced than individual games to make it realistic and they'd become a 'second' team, but as soon as the Rams (or whichever team you follow) come over - that's who I'm supporting. I’m fortunate (for Football purposes) in that I live in London so it’s easy to get to the games; before I moved here I could come once or twice a year due to the cost of the whole weekend and it’s unlikely that the people who come to a couple of NFL games a year here could afford or make the logistics work to attend 8 games a year. There’s a risk that whilst the fanbase for the game has expanded, after the novelty for the first year or two of having our own franchise has worn off it’s a much harder challenge to fill the stadium consistently. Changing the branding of the franchise to something relevant to the UK and losing the Chargers brand may help people think it’s their team rather than something just on loan.
I do think the current International Series is becoming tired – the two Wembley games this year had so many more cheap tickets being resold in the last week than I can remember before (I ended up going again on Sunday as we were able to pick up ridiculously cheap tickets) – and it’s getting to the stage where the NFL do either have to move a franchise here or look at what their overall European strategy is.
In summary business-wise and logistics-wise I could see a franchise in the UK working although it will take a new generation of fans on football to become fans of that team rather than us all switching our allegiance. The overriding thought though is the romantic in me hates the thought of teams being picked up and moved from place to place with no regard for their fanbase (no matter how large or small) and bringing a franchise to London just doesn’t sit right with me.