We did it a few years ago with a tandem MTB, trailer and rode between them (on roads), climbed up the m on rock (I’m not a climber so that was a laugh!) doing an 11 pitch route up Snowdon, a 2 pich route up Scafell and up the Ben on Tower ridge. We had the tandem-paraglider in the trailer to fly off the summits back down to the bike. It took us 5 riding days and 3 ascent days since the accent of each was a full day. Was strange and hard since we’d not been on a tandem before except for one hour ‘trial’ ride! Email me if you want route-help as we had a good route including mersey-ferry, Isle of Arran and Listmore and riding Wrynose and Hardnott passes.
The tamdem was Boxelders (of this forum), I bet he’d want to padd it on if he can – ha ha!!
C