HDX 70 Gal. Tough Storage Tote with Wheels
The only tote on this page anyone has reported fitting a folded Lectric into, even sideways, even on a bigger model. Sold at Home Depot, not Amazon, which is why the link goes straight to their page.
Install note
At 45 in x 23.92 in x 22.28 in exterior, this is the biggest tote we found and still falls 6.72 in short of the XP4 folded height of 29 in standing up. An XPremium owner made this exact tote work lying the bike on its side, but the XPremium is a larger bike than the XP4 in every folded dimension, and we found no report of an XP4 owner doing the same, so we are not carrying that verdict over. Standing up, it does not fit; on its side, unconfirmed for this bike.