Home Heating Cost Surge - On tenant alone?

[Ron Brady]

One of our 7 SFHs is on an oil heat furnace.  Our tenant, one of our very best, just messaged us:

"FYI, when I moved in, oil was $1.69/gallon. It's now $4.85. 

When we responded by asking him, "any suggestions?", He responded :"More blankets".  Shows he a) has a sense of humor and b) isn't trying to just place this challenge on us

In all seriousness, not quite sure what to do here. We also own the exact same-sized and styled home right next door and it is gas heat and they have no similar surge (yet, at least). Thus, we can see the challenge before our tenant to simply eat the entire new cost.  

Not that it matters, but as a family we're in favor of not buying Russian oil at the moment.  That stance was before we remembered that one of properties is oil heat.  We still take that stance, now with putting more of our money where our mouth is.

Our options:

1. Tenant foots entire additional cost in the next bill

2. We split the additional cost in the next bill--not sure how to split

3. We assume all or almost all of the cost in the next bill

4. Some other option

What would you do?