There is no other fifth gen option available to NATO.
I'm nitpicking a bit, but like you mentioned, China and Russia have limitations. I don't really buy that the J-20 is on the same level, and the Russian thing is an actual joke. So, "to anyone".
The Gripen is one of the best choices out there, and it does have a lot of stealth and EWAR capabilities that other fighters lack
EWAR sure, but it's totally unstealthy AFAIK. Survivability would depend on hitting something, landing in a field and getting back onto a truck before a counterattack can arrive. Which works for SAM units and artillery, I guess.
Which, maybe we should just invest in SAM units and sensors, honestly, if we're worried about a hostile US. I'm guessing it's a lot more cost effective, and would be nearly as effective early in a defencive conflict. The other medium-term option would be a jailbroken F-35 of some kind, but that's only possible once the alliance is well and truly dead (all the physical parts are available from somewhere else).