Hi there,
Well, like some others on here, we've got both cars and I've owned them for a long time; Elan since the mid 70s, Europa mid 80s. Both were daily cars when I bought them and both used for holidays away, in fact the Elan was used a lot for weekend camping - and that was with a frame tent !
In sunshine and on quiet country roads I prefer the Elan, mainly because I like convertibles. As you say it's low geared (3.5diff on mine) but on country roads I don't really see it as a problem. Ok, we were younger back then but still managed 2-3hr drives with a packed car for weekends away.
For something like a motorway trip then the Europa is far, far better. Mine is the 4sp and technically still "buzzy" with similar revs/mph as the Elan but the engine/gearbox are behind your head so I never really notice it. But the big factor is wind noise, the Europa has very little wind noise and that can be a bad thing because you can hear the rattles from everything else
Could you do weekends & 2-300 miles in a day ? well, we have and with no problem at all. If you want to cruise at 70/80/??? then it's going to be noisier than a modern car but far less than an Elan. Consider that back in the day Lotus did TC development by sending folks off to Italy & back for the weekend to check reliability, that's over 3,000 miles in a weekend on the prototypes.
In the UK we don't drive as far as you guys will in normal life (smaller country, etc) but we do have our moments. We'd go to Club Lotus weekends in either car and both are fine. Probably more luggage space in the Europa, the rear boot is smaller than the Elan but the front compensates. We also stowed stuff behind the seats in the Elan, something you can't do in the Europa but wife + clothes + "how many handbags
" for evenings were never an issue.
Finally - when we first moved here I'd do 380 mile round trips in a day to see parents. We never used the Elan/Europa but I would use the Elise because it's nippy; I was usually was shattered afterwards. In my opinion 400 miles/day in a Europa would be much more comfortable/quieter (but slower) than a modern day Elise. That might give you something else to think about - the Europa was well ahead of it's time and I'd say still holds well today.
Brian