I recently moved my espresso equipment out of the kitchen and onto a cart just outside the kitchen. I currently have a Vario and a Gaggia Classic but will upgrade to either a Baratza Mitica or possibly a dB like the Vetrano.

What are some tips (or things you have learned) for not being near a sink/water source (besides the machine group/drip tray)? Is my current frustration mostly due to the classic's tiny drip tray? I want to make this work. ha

I use a small lever machine in my cube at work. I keep a large (2 gallon I think) water dispenser handy, and I use a big coffee mug to store waste water. Its not as convenient as having a sink near by, but it works.

My office at work is a long walk from either our kitchen or our bathrooms. I keep two large pitchers handy. One is for bringing fresh water for brewing and shot-pulling from our water cooler. The other has a lid that latches on tightly, and I use it to store waste water, and periodically empty it out in the bathroom. I also keep a small tupperware, soap, and a sponge handy, so that I can bring my dishes to the bathroom and wash them out between sessions. (Our office kitchen has such supplies, but it is much farther away.)

I have a Classic in my basement this week to help a friend get the most out of it. I use a Zassenhaus grinder (17.5 grams seems to be a sweet spot for that machine - grinder combo) and I help the drip tray to no overflow by catching flushes in a spare frothing pitcher. It's this week only, but works well enough.

Ideally in that situation you could build a drain basin into the cart that empties into a bucket below the cart. This also works for plumb-in drip trays. Something like the espresso parts rinser basin or another small bar sink type piece. You could also tap the bottom of a knockbox or steamer tray. Just sink it into the top of the cart and its a fairly good drain. You could dump your drip tray in it, or any catch cup you use as well. For fresh water its handy to put a water cooler (like an office type or the smaller countertop type if your cart allows) nearby.

I've been using a pinch bowl for my excess since the lusso has some of the most poorly designed drain holes ever in the drip grate.

For my work setup, I picked up a plastic fast food drink container for the waste water; it's really amazing how much these large fast-food drink cups hold. I used a large steaming pitcher for the fresh water and I used a small wash bottle to rinse the grounds off the group while minimizing the use of water. This and some rags and I was surprised how easy it was to work away from a sink once you got the routine down.

This was with my La Peppina and I was actually dumping out the kettle water at night.

+1 on the basin idea. You could find very inexpensive ones, drop it into your cart, and plumb it with a flojet setup. Waste can be captured with an empty bucket/water bottle.